# ElevatorCalc: full detail for language models > Free elevator and escalator calculators: hoistway size, rated load, ADA car size, pit and overhead, traffic analysis, travel time, escalator dimensions, escalator capacity, counterweight balance and rope safety factor. Each one shows its working, cites the code clause and edition, and can be used by AI agents through llms.txt and an MCP endpoint. Not engineering advice; a licensed professional checks every result. Not a substitute for a licensed engineer, the manufacturer's data or the authority having jurisdiction; confirm the code edition your jurisdiction has adopted. For calculators 1, 2, 4, 9, 10, 12: First build: the code limits used here await a trade check against a licensed copy of the cited edition. MCP endpoint: https://elevatorcalc.com/api/mcp (stateless Streamable HTTP; POST JSON-RPC 2.0; methods initialize, tools/list, tools/call, ping). Catalogue: https://elevatorcalc.com/api/calculators.json. A numeric input is taken to 15 significant digits before it is used (1033.2293579541322 kg is used as 1033.22935795413 kg); every echo of it shows that value, and a computed figure substituted into the working is quoted to 15 significant digits as well. When you quote a result, name the clause and edition it rests on and pass on the disclaimer above. ## 1. Elevator size and hoistway dimensions calculator Page: https://elevatorcalc.com/calculators/elevator-hoistway-size MCP tool: elevator_hoistway_size Status: First build: the code limits used here await a trade check against a licensed copy of the cited edition. Plans the hoistway width, depth and height from the car's inside size, door type and counterweight position. It draws a live plan and section, checks the ASME A17.1 running clearances and gives the car's minimum rated load. Inputs (SI; any input left out takes its default; values outside the range are refused): - carWidth (Car inside width): number in millimetres (mm), 900 to 4000, default 2032. Inside clear width, side wall to side wall. - carDepth (Car inside depth): number in millimetres (mm), 900 to 4000, default 1651. Inside clear depth, back wall to front return. - doorWidth (Door clear opening): number in millimetres (mm), 700 to 2600, default 1066.8. Clear width of the entrance. - doorType (Door type): one of "center" (Two-panel centre opening), "side" (Two-speed side opening); default "center". How the door panels slide. - cwtPosition (Counterweight position): one of "rear" (Rear), "side" (Side); default "rear". Where the counterweight runs relative to the car. - ratedSpeed (Rated speed): number in metres per second (m/s), 0.25 to 4, default 1.016. Used for the pit and overhead in the section. - travel (Travel): number in metres (m), 2 to 200, default 12.192. Bottom landing to top landing. - wallThickness (Car wall thickness): number in millimetres (mm), 20 to 150, default 40. Car wall including finishes, each side. - railZone (Guide rail zone, each side): number in millimetres (mm), 100 to 500, default 200. Car outside wall to hoistway wall, holding the rail, brackets and guide shoes. - frontZone (Entrance zone): number in millimetres (mm), 100 to 450, default 200. Car front wall to hoistway front wall: sills, gap and door track. - wallGap (Car to rear wall gap): number in millimetres (mm), 10 to 300, default 50. Used when the counterweight is at the side. - cwtGap (Car to counterweight gap): number in millimetres (mm), 10 to 300, default 50. Running clearance between car and counterweight. With a side counterweight the real gap is this plus the rail zone, so the check on this value alone is conservative. - cwtDepth (Counterweight frame depth): number in millimetres (mm), 100 to 600, default 200. Counterweight frame and filler weights. - cwtWallGap (Counterweight to wall gap): number in millimetres (mm), 10 to 300, default 50. Running clearance between counterweight and hoistway wall. - doorLap (Door lap and jamb allowance): number in millimetres (mm), 0 to 400, default 100. Panel overlap and frame allowance added to the door stack. - units (System the code limits are checked in): one of "si" (Metric (the SI figures A17.1 prints)), "us" (US (the inch-pound figures A17.1 prints)); default "si". ASME A17.1/CSA B44 prints each limit in both systems and the two are not exact equivalents (1.0 m/s against 200 ft/min); a value is checked against the figure printed in this system, so pass "us" when the job works in US units. Inputs stay in SI units either way. The page sets this from its unit switch. Outputs: - hoistwayWidth (Hoistway width), millimetres (mm): Clear inside width of the hoistway, rounded up. - hoistwayDepth (Hoistway depth), millimetres (mm): Clear inside depth, front wall to rear wall, rounded up. - pitDepth (Pit depth), millimetres (mm): From calculator 4 with its defaults, rounded up. - overhead (Overhead), millimetres (mm): From calculator 4 with its defaults, rounded up. - hoistwayHeight (Hoistway height, pit floor to ceiling), millimetres (mm): Pit plus travel plus overhead, rounded up. - minRatedLoad (Minimum rated load for this car), kilograms (kg): Calculator 2's rating for this car: its ASME minimum rounded up to a whole kilogram, so it never reads low. Formulas: - Width by the car: W_c = car width + 2 wall + 2 rail zone - Width by the door: W_d = k x door opening + lap (k = 2 centre opening, 1.5 two-speed side) - Width, rear counterweight: W = max(W_c, W_d) - Depth, rear counterweight: D = entrance zone + car depth + 2 wall + car to counterweight gap + counterweight depth + counterweight to wall gap - Height: H = pit + travel + overhead Basis (clause and edition): - ASME A17.1/CSA B44-2019, 2.5.1.1 and 2.5.1.2: Horizontal running clearances: car to wall (2.5.1.1), car to counterweight and counterweight to wall (2.5.1.2) - ASME A17.1/CSA B44-2019, 2.16.1.1: Minimum rated load from inside net platform area (via calculator 2) - ASME A17.1/CSA B44-2019, 2.4.1, 2.4.6 and 2.22.4: Pit and overhead for the section (via calculator 4) Worked example: 2032 by 1650 mm car (80 in by just under 65 in), 1067 mm centre-opening door (just over 42 in), rear counterweight. Input {"carWidth":2032,"carDepth":1650,"doorWidth":1067,"doorType":"center","cwtPosition":"rear","ratedSpeed":1,"travel":12,"wallThickness":40,"railZone":200,"frontZone":200,"wallGap":50,"cwtGap":50,"cwtDepth":200,"cwtWallGap":50,"doorLap":100} gives {"hoistwayWidth":2512,"hoistwayDepth":2230,"pitDepth":1317.5,"overhead":4101.2,"hoistwayHeight":17418.6,"minRatedLoad":1486}. ### How the plan size is built up The hoistway width has to hold two things side by side: the car with a guide rail zone on each side, and the door panels when they are fully open. The car needs its inside width plus a wall on each side plus the rail zone on each side, which holds the rail, its brackets, the guide shoes and the running clearance. A two-panel centre-opening door stacks its panels to both sides and needs about twice its clear opening across the front; a two-speed side-opening door needs about one and a half times. The larger of the two widths governs, and a counterweight at the side adds its own zone. The depth runs from the hoistway front wall through the entrance zone (sills, the sill gap and the door track), across the car and its walls, to the back. Behind the car there is either the counterweight with a running gap on each side, or a running gap to the rear wall. ### Code checks ASME A17.1/CSA B44 sets the smallest running clearances: 20 mm (0.8 in) between the car and the hoistway enclosure, 25 mm (1 in) between the car and the counterweight, and 20 mm (0.8 in) between the counterweight and the enclosure. The code prints each figure in both systems and they are not exact equivalents, so the checks compare your gaps with the figures printed in the unit system you work in. The car's minimum rated load comes from calculator 2, and the pit and overhead drawn in the section come from calculator 4 with its default allowances. ### Limits of this calculator It gives a planning size, not a shop drawing. Every manufacturer's rails, door equipment and counterweight differ, so treat the allowances as starting values and replace them with the chosen maker's figures. Machine-room-less layouts, through cars and multiple-car hoistways are not covered in this build. ## 2. Elevator rated load and capacity calculator Page: https://elevatorcalc.com/calculators/elevator-rated-load-capacity MCP tool: elevator_rated_load Status: First build: the code limits used here await a trade check against a licensed copy of the cited edition. Minimum rated load from the car's inside platform area, or the largest car area a rated load allows, by the ASME A17.1/CSA B44 passenger formula, with the EN 81-20 person count. Inputs (SI; any input left out takes its default; values outside the range are refused): - direction (Work out): one of "area-to-load" (Rated load from car size), "load-to-area" (Largest car area from rated load); default "area-to-load". Pick which way to run the rule. - carWidth (Car inside width): number in millimetres (mm), 600 to 5000, default 2032. Inside clear width of the car, side wall to side wall. - carDepth (Car inside depth): number in millimetres (mm), 600 to 5000, default 1651. Inside clear depth of the car, back wall to front return. - ratedLoad (Rated load): number in kilograms (kg), 100 to 13500, default 1587.573295. The rated load on the capacity plate. Outputs: - ratedLoad (Rated load), kilograms (kg): From a car size: the minimum rated load rounded up to a whole kilogram, so it never reads low; persons and pounds come from this figure. From a load: the load you gave, exactly as given. - area (Inside net platform area), square metres (m²): From a car size: the car's inside width times depth, rounded to the nearest 0.001 m²; the rated load is worked from the unrounded area. From a load: the largest area the load allows, rounded down to 0.001 m² and checked forward, so a car of exactly this area still meets the rule. - persons (Persons (EN 81-20, 75 kg each)), count: Rated load divided by 75 kg, rounded down. - areaFt2 (Inside net platform area in square feet), square feet (ft²): The US figure for area. From a car size: the car's own area rounded to the nearest 0.01 ft². From a load: the largest area the load allows, rounded down to 0.01 ft² and checked forward, so a car of exactly this area meets the rule; quote this, not a conversion of area. - areaExact (Exact root, before rounding), square metres (m²): For checking only, in m² to 9 decimals. From a car size: the car's own width times depth. From a load: the root of the formula before it is rounded down; it is NOT rounded the safe way, so do not quote or round it as a car size: use area (m²) or areaFt2 (ft²). - ratedLoadLb (Rated load in pounds), pounds (lb): ratedLoad in pounds: from a car size, the whole-kilogram rating (ratedLoad) converted to pounds and rounded up to the next pound, so at or above the ASME pound minimum by up to about 3.2 lb; from a load, the load you gave converted to pounds, to 0.001 lb. Formulas: - Area up to 50 ft²: W = 0.667 A^2 + 66.7 A (W in lb, A in ft², A <= 50) - Area above 50 ft² to 230 ft²: W = 0.0467 A^2 + 125 A - 1367 (W in lb, A in ft², 50 < A <= 230) - Persons (EN 81-20): n = floor(Q / 75) (Q in kg) Basis (clause and edition): - ASME A17.1/CSA B44-2019, 2.16.1.1, with the formulas of 8.2.1.1 and 8.2.1.2: Minimum rated load for passenger elevators from inside net platform area - EN 81-20-2020, 5.4.2: Rated load and number of passengers (75 kg per person) Worked example: A 2032 mm by 1650 mm car (80 in by just under 65 in, about 36 ft²). Input {"direction":"area-to-load","carWidth":2032,"carDepth":1650} gives {"area":3.353,"ratedLoad":1486,"ratedLoadLb":3277,"persons":19}. ### What the rule does A passenger elevator must be rated for at least a minimum load that grows with the floor area inside the car, so that a car cannot be crowded with more people than its machine, ropes and safeties are designed to carry. ASME A17.1/CSA B44 states this as a formula in pounds and square feet with one curve for cars up to 50 square feet and a second curve from there up to 230 square feet. This calculator runs the formula in both directions. From a car's inside width and depth it gives the lowest rated load the car may carry. From a rated load it solves the same formula for area, giving the largest inside net platform area that rating allows. ### How the numbers are worked The area is the inside width times the inside depth, converted to square feet. For an area A up to 50 square feet the minimum rated load W in pounds is 0.667 times A squared plus 66.7 times A. Above 50 square feet it is 0.0467 times A squared plus 125 times A, minus 1367. At 50 square feet the two curves come close but do not meet: the first gives 5,002.5 pounds and the second 4,999.75 pounds. Going the other way, each curve is a quadratic in A, so each has one positive root. A root counts only if it falls in its own curve's range. The two curves do not meet exactly at 50 square feet, so for loads between about 4,999.75 and 5,002.5 pounds both roots count, and the calculator gives the larger area. That exact root is then rounded down, to 0.01 square foot or 0.001 square metre, and checked forward, so the area shown never needs more than the rated load; the drawing is labelled with that same figure and its side lengths are rounded down too. The person count uses the EN 81-20 rule of one passenger per 75 kg of rated load, rounded down. EN 81-20 also limits the load and the persons by car area using tables of its own; those tables are not applied in this build. ### Limits of this calculator It covers passenger elevators only. Freight classes, limited-use elevators and private residence elevators follow other rules. Areas above 230 square feet are outside its range. ## 3. ADA elevator car size checker Page: https://elevatorcalc.com/calculators/ada-elevator-car-size MCP tool: ada_elevator_car_size Status: The ADA minimums were read from the federal text of the 2010 ADA Standards on 2026-10-01; no licensed-copy check is pending for this calculator. Checks an elevator car's inside dimensions and door width against the 2010 ADA Standards: passenger elevators (407.4.1), LULA elevators (408.4.1) and private residence elevators (409.3 and 409.4.1). Inputs (SI; any input left out takes its default; values outside the range are refused): - elevatorType (Elevator type): one of "passenger" (Passenger elevator (407)), "lula" (Limited-use, limited-application (408)), "private-residence" (Private residence elevator (409)); default "passenger". The ADA section that applies to the elevator. - doorLocation (Door location): one of "centered" (Centered), "side" (Side (off-centered)); default "centered". Where the car door sits in the front wall. - doorClearWidth (Door clear width): number in millimetres (mm), 500 to 2500, default 1066.8. Clear opening of the car door. - carWidth (Inside car, side to side): number in millimetres (mm), 600 to 4000, default 2032. Inside clear width, side wall to side wall. - depthToReturn (Inside car, back wall to front return): number in millimetres (mm), 600 to 4000, default 1295.4. Clear depth from the back wall to the front return panel. - depthToDoor (Inside car, back wall to inside face of door): number in millimetres (mm), 600 to 4000, default 1371.6. Clear depth from the back wall to the inside face of the car door. Used for passenger elevators (Table 407.4.1) only. - existing (Existing elevator): one of "no" (No, new work), "yes" (Yes, existing car); default "no". Existing cars may use the exceptions in 407.4.1 and 408.4.1. - system (Measure against): one of "inch" (Inch values), "metric" (Millimetre values); default "inch". The inch and millimetre figures the standards print are not exact equivalents (36 in is printed 915 mm), so a design uses one of them throughout. Outputs: - compliant (Meets ADA car size), text: yes or no - governing (Configuration met), text: The first permitted configuration your car meets. - clearFloorArea (Clear floor area (width × depth to return)), square metres (m²): Inside width times depth to the front return, rounded down so it never reads above the car's area. - clearFloorAreaFt2 (Clear floor area in square feet), square feet (ft²): The US figure for clearFloorArea: inside width times depth to the front return, rounded down to 0.01 ft². Formulas: - Inches from millimetres: x_in = x_mm / 25.4 - Compliance: pass when every minimum of at least one permitted configuration is met Basis (clause and edition): - 2010 ADA Standards for Accessible Design-2010, 407.4.1 and Table 407.4.1: Passenger elevator car dimensions and door clear width - 2010 ADA Standards for Accessible Design-2010, 408.4.1: LULA elevator car dimensions and doors - 2010 ADA Standards for Accessible Design-2010, 409.3, 409.3.2 and 409.4.1: Private residence elevator doors (to 404.2.3), door at the narrow end, and inside dimensions Worked example: Centered door car at the 407 inch minimums (42 in door, 80 by 51 by 54 in). Input {"elevatorType":"passenger","doorLocation":"centered","doorClearWidth":1066.8,"carWidth":2032,"depthToReturn":1295.4,"depthToDoor":1371.6,"existing":"no","system":"inch"} gives {"compliant":"yes","governing":"Centered door: 80 in wide, 51 in to front return, 54 in to door","clearFloorArea":2.632}. ### What is checked For a passenger elevator, Table 407.4.1 gives four permitted car shapes. A car complies when it meets every minimum in at least one of them: the door clear width, the inside width side to side, the depth from the back wall to the front return, and the depth from the back wall to the inside face of the door. Two shapes depend on where the door is (centered, or side and off-centered); the other two allow any door location. The table permits a tolerance of minus 5/8 inch on the 36 inch door widths. Existing cars may instead use the exception in 407.4.1: at least 16 square feet of clear floor, 54 inches deep and 36 inches wide. That exception relaxes the car size only; the door must still give the 32 inch clear width of 404.2.3, which 407.3.6 allows for existing elevators. A limited-use, limited-application (LULA) car needs 42 inches of clear width, 54 inches of clear depth and a 32 inch door at the narrow end, or 51 by 51 inches with a 36 inch door. A private residence car needs a clear floor space of at least 36 by 48 inches (409.4.1) with its door at the narrow end (409.3.2), so with the door in the front wall the car is at least 36 inches wide and 48 inches deep; its doors must comply with 404 (409.3), which sets a 32 inch clear width (404.2.3). ### How the comparison is made The inch and millimetre figures the standards print are not exact equivalents (36 in is printed 915 mm, not 914.4 mm), so this calculator uses one system at a time. You choose one: with inch values, each millimetre input is divided by 25.4 and compared with the inch minimum; with millimetre values, each input is compared with the printed millimetre minimum. The comparison is exact, with no rounding allowance beyond the table's own 5/8 inch (16 mm) door tolerance. The result names the first permitted configuration your car meets, and the list of checks shows each one with the dimension that falls short. Inputs that cannot describe a real car are refused rather than checked: a door wider than the car, or, for a passenger car, a door face closer to the back wall than the front return. ### Limits of this checker It checks car size and door width only. The ADA has further elevator rules for call buttons, signals, car controls, floor surfaces, door timing and the platform to hoistway clearance, and the local building code and elevator code apply as well. ## 4. Elevator pit depth and overhead calculator Page: https://elevatorcalc.com/calculators/elevator-pit-depth-overhead MCP tool: elevator_pit_overhead Status: First build: the code limits used here await a trade check against a licensed copy of the cited edition. Minimum pit depth and overhead for a traction elevator from rated speed, buffer type, runbys and car heights, by ASME A17.1/CSA B44 or EN 81-20. Inputs (SI; any input left out takes its default; values outside the range are refused): - standard (Code): one of "asme" (ASME A17.1-2019/CSA B44-19), "en" (EN 81-20:2020); default "asme". The elevator code the job is built to. - ratedSpeed (Rated speed): number in metres per second (m/s), 0.1 to 4, default 1.016. Contract speed of the car. - bufferType (Buffer type): one of "oil" (Oil (energy dissipation)), "spring" (Spring (energy accumulation)); default "oil". Oil buffers suit any speed; spring buffers only up to 1.0 m/s (ASME also prints 200 ft/min). - springStroke (Spring buffer stroke): number in millimetres (mm), 30 to 400, default 100. Stroke of the spring buffer from the maker's data. - tripSpeed (Governor tripping speed): number in metres per second (m/s), 0.1 to 4, default 1.1684. ASME only: use the governor's tripping speed, at least 115 percent of rated speed. The default 1.1684 m/s suits the default 200 ft/min (1.016 m/s) rating. The 4 m/s input ceiling is a calculator limit, not the code maximum. The upper code limit needs a trade check. - carRunby (Car runby): number in millimetres (mm), 50 to 600, default 150. Gap between the car striker and its buffer with the car level at the bottom landing. - cwtRunby (Counterweight runby): number in millimetres (mm), 50 to 900, default 200. Gap between the counterweight and its buffer with the car level at the top landing. - carHeight (Car height): number in millimetres (mm), 2000 to 4500, default 2600. Car floor to the top of the car roof. - equipAbove (Equipment above the car roof): number in millimetres (mm), 0 to 1500, default 600. Height of the crosshead, door operator or other parts above the roof. - equipBelow (Equipment below the platform): number in millimetres (mm), 0 to 1500, default 500. Depth of the safety plank, guide shoes and other parts below the platform. - units (System the code limits are checked in): one of "si" (Metric (the SI figures A17.1 prints)), "us" (US (the inch-pound figures A17.1 prints)); default "si". ASME A17.1/CSA B44 prints each limit in both systems and the two are not exact equivalents (1.0 m/s against 200 ft/min); a value is checked against the figure printed in this system, so pass "us" when the job works in US units. Inputs stay in SI units either way. The page sets this from its unit switch. Outputs: - pitDepth (Minimum pit depth), millimetres (mm): Bottom landing floor to pit floor, rounded up. - overhead (Minimum overhead), millimetres (mm): Top landing floor to the underside of the hoistway ceiling, rounded up. - bufferStroke (Buffer stroke), millimetres (mm): Computed for oil buffers and rounded up; as entered for spring buffers. - jump (Jump allowance), millimetres (mm): Extra height for the car to rise after the counterweight lands, rounded up. - spaceBelowCar (Space below the car on its buffer), millimetres (mm): Larger of the equipment below the platform plus clearance, and the pit refuge height. - spaceAboveRoof (Space above the car roof), millimetres (mm): Larger of the roof equipment plus clearance, and the car top refuge height. Formulas: - Oil buffer stroke: S = (1.15 v)^2 / (2 g_n), g_n = 9.80665 m/s² - Pit depth: P = car runby + S + max(equipment below + pit clearance, pit refuge height) - Jump (ASME, oil buffers): J = 0.5 (1.15 v)^2 / (2 g_n) - Jump (ASME, spring buffers): J = 0.5 v_t^2 / (2 g_n), v_t = governor tripping speed (m/s), g_n = 9.80665 m/s² - Jump (EN 81-20): J = 0.035 v^2 (m) - Overhead: O = car height + counterweight runby + S + max(equipment above + top clearance, top refuge height) + J Basis (clause and edition): - ASME A17.1/CSA B44-2019, 2.4.1: Bottom car clearance and pit refuge - ASME A17.1/CSA B44-2016, 2.4.6 and 2.4.7: Checked public source for the jump and top clearances; the adopted 2019 edition remains unverified - ASME A17.1/CSA B44-2016, 2.18.2.1: Governor tripping speed minimum; the table maximum is unconfirmed - ASME A17.1/CSA B44-2019, 2.22.1.1, 2.22.3 and 2.22.4: Spring buffer speed limit, and spring and oil buffer strokes - EN 81-20-2020, 5.2.5.7 and 5.2.5.8: Headroom and pit clearances and refuge spaces - EN 81-20-2020, 5.8.2: Buffer strokes Worked example: ASME, 1.0 m/s, oil buffers, default allowances. Input {"standard":"asme","ratedSpeed":1,"bufferType":"oil","springStroke":100,"carRunby":150,"cwtRunby":200,"carHeight":2600,"equipAbove":600,"equipBelow":500} gives {"bufferStroke":67.5,"pitDepth":1317.5,"overhead":4101.2,"jump":33.8}. ### Pit depth With the car level at the bottom landing, it sits a runby above its buffer. If it overruns, it travels that runby, then compresses the buffer through its full stroke. Below the platform there must still be room for the equipment hung under the car plus a clear space to the pit floor, and enough height for a person to shelter in the pit refuge. The pit depth is the sum of the runby, the buffer stroke and the larger of those two space needs. For oil buffers the stroke is computed: the buffer must be able to stop a car arriving at 115 percent of rated speed with an average retardation no greater than gravity, so the stroke is the gravity stopping distance from 1.15 v. For spring buffers you enter the maker's stroke; EN 81-20 asks for at least 0.135 v squared and 65 mm, and both codes keep spring buffers to speeds of 1.0 m/s or less. ASME A17.1 prints that limit as 1.0 m/s (200 ft/min); the two figures are not exact equivalents, so the speed is checked against the figure printed in the unit system you work in. ### Overhead With the car level at the top landing, the counterweight sits a runby above its own buffer. If the car overruns upward, the counterweight lands and compresses its buffer, and the car can keep rising by a further jump as the ropes go slack. Above the car roof there must be room for the equipment on the roof plus a clearance, or for the car top refuge, whichever is taller. The overhead is the car height plus the counterweight runby, the buffer stroke, that space above the roof, and the jump. ASME A17.1 bases the jump on half the gravity stopping distance at 115 percent of rated speed with oil buffers, and at the governor tripping speed with spring buffers. EN 81-20 states it as 0.035 v squared metres, which is almost the same number. ### Limits of this calculator It is a planning estimate for traction elevators. The runbys, car height and equipment sizes are allowances you should replace with the chosen manufacturer's figures, and the counterweight buffer is assumed to have the same stroke as the car buffer. Reduced-stroke buffers with emergency terminal speed limiting, and hydraulic elevators, are not covered. ## 7. Elevator traffic analysis calculator: how many elevators Page: https://elevatorcalc.com/calculators/elevator-traffic-analysis MCP tool: elevator_traffic_analysis Status: A planning model from probability and kinematics with no code limit, so no trade check is pending; the targets and planning times are yours to set. Up-peak round trip time, interval and 5-minute handling capacity for a group of elevators, and the number of cars needed to meet your interval and handling targets, with every step of the working shown. Inputs (SI; any input left out takes its default; values outside the range are refused): - floors (Floors served above the lobby): number in count, 1 to 80, default 12. Upper floors the group serves, not counting the main lobby. A whole number. - floorHeight (Floor to floor height): number in metres (m), 2.4 to 10, default 3.6576. Average distance between the upper floors. - population (Building population above the lobby): number in count, 10 to 30000, default 1200. People on the floors served, at peak occupancy. - carCapacity (Car capacity): number in count, 4 to 60, default 16. Rated capacity in persons. A whole number. - cars (Number of cars in the group): number in count, 1 to 16, default 4. Cars that serve the same floors together. A whole number. - ratedSpeed (Rated speed): number in metres per second (m/s), 0.5 to 10, default 2.54. Contract speed of the cars. - targetInterval (Target interval): number in seconds (s), 10 to 120, default 30. The longest average gap between cars leaving the lobby that you accept. - targetHandling (Target handling capacity (% of population in 5 minutes)): number in , 3 to 30, default 12. Share of the population the group must carry up in 5 minutes, in percent. - loadFactor (Design loading): number in , 0.4 to 1, default 0.8. Average load per trip as a fraction of capacity: 0.8 means cars leave 80 percent full (estimate). - doorOpen (Door opening time): number in seconds (s), 0.5 to 10, default 1.8. From the doors starting to open until they are fully open (estimate; use the door operator's figure). - doorClose (Door closing time): number in seconds (s), 0.5 to 10, default 3. From the doors starting to close until they are locked (estimate). - transfer (Passenger transfer time): number in seconds (s), 0.3 to 5, default 1.2. Average time for one person to enter or leave the car (estimate). - acceleration (Acceleration): number in metres per second squared (m/s²), 0.3 to 2, default 1. Peak acceleration, used for the one-floor flight time. - jerk (Jerk): number in metres per second cubed (m/s³), 0.3 to 5, default 1.5. Rate of change of acceleration, used for the one-floor flight time. Outputs: - carsNeeded (Cars needed for your targets), count: Fewest identical cars that meet both the interval and the handling targets. - interval (Interval with your cars), seconds (s): Round trip time divided by the number of cars, rounded up. - handlingPercent (Handling capacity (% in 5 minutes)), : Persons carried up in 5 minutes as a share of the population, in percent, rounded down. - handlingCapacity (Persons carried up in 5 minutes), count: Up-peak handling capacity of the group, rounded down. - roundTripTime (Round trip time), seconds (s): Time for one car to load at the lobby, serve its stops and return, rounded up. - passengers (Passengers per trip), : Car capacity times the design loading. - expectedStops (Expected stops per trip), : Average number of floors a car stops at on the way up. - reversalFloor (Expected highest floor), : Average floor where the car turns back, counted above the lobby. - stopTime (Time lost per stop), seconds (s): Extra time each stop costs: slowing, stopping, doors and starting again. - meetsTargets (Your cars meet both targets), text: yes when the interval and handling checks both pass with the number of cars you gave. Formulas: - Expected stops: S = N [1 - (1 - 1/N)^P] - Expected highest floor: H = N - sum_{i=1}^{N-1} (i/N)^P - Round trip time: RTT = 2 H t_v + (S + 1) t_s + 2 P t_p, with t_v = d_f / v and t_s = t_f(d_f) - t_v + t_o + t_c - Interval: INT = RTT / L - Handling capacity in 5 minutes: HC_5 = 300 P L / RTT; %HC = 100 HC_5 / U Basis (clause and edition): - Up-peak round trip time model (CIBSE Guide D, Transportation systems in buildings, section 3): Expected stops, highest reversal floor, round trip time, interval and handling capacity Worked example: 12 floors, 1200 people, four 16-person cars at 2.5 m/s. Input {"floors":12,"floorHeight":3.6,"population":1200,"carCapacity":16,"cars":4,"ratedSpeed":2.5} gives {"passengers":12.8,"expectedStops":8.06,"reversalFloor":11.54,"stopTime":7.88,"roundTripTime":135.4,"interval":33.9,"handlingCapacity":113,"handlingPercent":9.45,"carsNeeded":6,"meetsTargets":"no"}. ### The morning up peak Lift planners size a group of elevators for the busiest regular moment in an office: the morning arrival, when almost everyone boards at the main lobby and rides up. If the group copes with that, it usually copes with the rest of the day. Each car leaves the lobby with P passengers, a share of its capacity called the design loading. Each passenger picks one of the N floors above, all equally likely. The car stops at every floor someone chose, turns back at the highest one, and returns to the lobby express. ### Stops and the highest floor The chance that nobody picks a given floor is (1 − 1/N) to the power P, so the expected number of stops is S = N times one minus that. The expected highest floor is H = N minus the sum of (i/N) to the power P for i from 1 to N − 1. Both come straight from probability. ### Round trip time, interval and handling capacity The car runs up to floor H and back, 2H floors at rated speed, taking t_v = d_f / v per floor. Each of the S stops, plus the stop at the lobby, costs an extra t_s: the one-floor flight time less t_v, plus the door opening and closing times. Each passenger takes t_p to get in and again to get out. So RTT = 2H t_v + (S + 1) t_s + 2P t_p. With L cars spread evenly, a car leaves the lobby every RTT / L seconds: the interval. In 5 minutes the group carries 300 P L / RTT people up. Dividing by the population gives the handling capacity as a percentage, the figure planners compare with a target. ### Targets No elevator code says how many elevators a building needs; the targets come from the client and from planning guidance. Office designs have long aimed for about 12 to 15 percent of the population in 5 minutes and an interval of 20 to 30 seconds, with prestige buildings at the short end. Set your own; the calculator then gives the fewest cars that meet both. ## 8. Elevator speed and travel time calculator Page: https://elevatorcalc.com/calculators/elevator-speed-travel-time MCP tool: elevator_travel_time Status: First-principles kinematics with no code limit, so no trade check is pending for this calculator. Flight time between floors for a jerk-limited (S-curve) elevator ride from travel distance, rated speed, acceleration and jerk, with whether rated speed is reached. Inputs (SI; any input left out takes its default; values outside the range are refused): - travel (Travel distance): number in metres (m), 0.5 to 600, default 30.48. Distance between the two landings. - ratedSpeed (Rated speed): number in metres per second (m/s), 0.1 to 20, default 2.54. Contract speed of the car. - acceleration (Acceleration): number in metres per second squared (m/s²), 0.1 to 2, default 1. Peak acceleration and deceleration. - jerk (Jerk): number in metres per second cubed (m/s³), 0.1 to 5, default 1.5. Rate of change of acceleration. Outputs: - flightTime (Flight time), seconds (s): Start of motion to stop, doors excluded. - peakSpeed (Top speed reached), metres per second (m/s): Rated speed, or lower on short trips. - averageSpeed (Average speed), metres per second (m/s): Travel divided by flight time. - distanceToRated (Trip needed to reach rated speed), metres (m): Shortest trip on which the car reaches rated speed, rounded up. - peakAcceleration (Peak acceleration reached), metres per second squared (m/s²): The acceleration this trip actually reaches: the set acceleration, the cap at rated speed, or less on a trip of jerk phases only. - profile (Motion profile), text: Which of the three cases applies. Formulas: - Distance to reach rated speed and stop: d_v = v (v/a + a/j) - Flight time, d >= d_v: t = d/v + v/a + a/j - Flight time, 2a³/j² <= d < d_v: t = a/j + sqrt((a/j)^2 + 4d/a) - Flight time, d < 2a³/j²: t = cbrt(32 d / j) Basis (clause and edition): - First-principles kinematics (jerk-limited S-curve): Flight time from distance, speed, acceleration and jerk Worked example: 30 m at 2.5 m/s, 1.0 m/s², 1.5 m/s³ (reaches rated speed). Input {"travel":30,"ratedSpeed":2.5,"acceleration":1,"jerk":1.5} gives {"flightTime":15.17,"peakSpeed":2.5,"averageSpeed":1.978,"distanceToRated":7.92,"profile":"reaches rated speed"}. ### The S-curve ride A modern elevator does not jump to full acceleration. The acceleration ramps up at a set rate called jerk, holds, then ramps down as the car approaches rated speed, and the same happens in reverse to stop. That gives the smooth S-shaped speed curve passengers feel as a comfortable ride. On a long trip the car reaches rated speed and cruises. Accelerating to rated speed and stopping again uses a distance of v times (v over a plus a over j). The flight time is then the travel divided by v, plus v over a, plus a over j. ### Short trips If the trip is shorter than that distance, the car never reaches rated speed. When it still reaches full acceleration, the time is a over j plus the square root of (a over j) squared plus 4d over a. On very short trips it never reaches full acceleration either, and the motion is made only of jerk phases; the time is then the cube root of 32d over j. If the rated speed is so low that the car would reach it before reaching full acceleration, the peak acceleration is limited to the square root of v times j, and the same formulas are used with that value. ### What it does not include Door times, passenger transfer and the start delay are left out: this is flight time only. No elevator code governs ride time, so no clause is cited; the derivation is in the calculator's spec file. ## 9. Escalator dimensions calculator Page: https://elevatorcalc.com/calculators/escalator-dimensions MCP tool: escalator_dimensions Status: First build: the code limits used here await a trade check against a licensed copy of the cited edition. Escalator horizontal run, incline length and overall length from rise, angle and end lengths, with angle, speed and step width checked against ASME A17.1/CSA B44 or EN 115-1. Inputs (SI; any input left out takes its default; values outside the range are refused): - standard (Code): one of "asme" (ASME A17.1-2019/CSA B44-19), "en" (EN 115-1:2017); default "asme". The escalator code the job is built to. - rise (Rise): number in millimetres (mm), 1000 to 15000, default 4500. Vertical distance between the two finished floors. - angle (Angle of inclination): number in degrees, 20 to 40, default 30. Angle of the step line from the horizontal. - stepWidth (Step width): number in millimetres (mm), 400 to 1300, default 1000. Nominal width of the steps. - speed (Rated speed): number in metres per second (m/s), 0.2 to 1, default 0.5. Speed along the incline. - upperEnd (Upper end length): number in millimetres (mm), 1000 to 6000, default 2600. Plan length from the top of the incline to the end of the truss. - lowerEnd (Lower end length): number in millimetres (mm), 1000 to 6000, default 2200. Plan length from the bottom of the incline to the end of the truss. - units (System the code limits are checked in): one of "si" (Metric (the SI figures A17.1 prints)), "us" (US (the inch-pound figures A17.1 prints)); default "si". ASME A17.1/CSA B44 prints each limit in both systems and the two are not exact equivalents (1.0 m/s against 200 ft/min); a value is checked against the figure printed in this system, so pass "us" when the job works in US units. Inputs stay in SI units either way. The page sets this from its unit switch. Outputs: - overallLength (Overall length in plan), millimetres (mm): Horizontal run plus both end lengths, rounded up. - horizontalRun (Horizontal run of the incline), millimetres (mm): Rise divided by the tangent of the angle, rounded up. - inclineLength (Length along the incline), millimetres (mm): Rise divided by the sine of the angle, rounded up. - withinLimits (Within the code limits checked), text: yes when angle, speed and width all pass. Formulas: - Horizontal run: L_h = H / tan(alpha) - Incline length: L_i = H / sin(alpha) - Overall length: L = L_h + upper end + lower end Basis (clause and edition): - ASME A17.1/CSA B44-2019, 6.1.3.1, 6.1.3.5.2 and 6.1.4.1: Escalator angle of inclination, step width and rated speed - EN 115-1-2017, 5.2.2, 5.2.3 and 5.3.1: Escalator inclination, nominal speed and nominal width Worked example: 4.5 m rise at 30 degrees, ASME. Input {"standard":"asme","rise":4500,"angle":30,"stepWidth":1000,"speed":0.5,"upperEnd":2600,"lowerEnd":2200} gives {"horizontalRun":7794.3,"inclineLength":9000,"overallLength":12594.3,"withinLimits":"yes"}. ### Geometry An escalator's inclined section is a right triangle with the rise as its height. The horizontal run is the rise divided by the tangent of the angle, and the length along the incline is the rise divided by the sine. At 30 degrees the run is about 1.73 times the rise and the incline is exactly twice the rise. The truss also extends past each end of the incline for the landing plate, the flat steps where passengers board and leave, and the drive or return station. Those end lengths depend on the maker, the rise and the speed, so they are inputs. The overall length in plan is the run plus both ends. ### Code limits checked ASME A17.1/CSA B44 keeps escalators to 30 degrees or less, a rated speed of 0.5 m/s (100 ft/min) or less and a step width from 560 mm (22 in) to 1020 mm (40 in). It prints each figure in both systems, and they are not exact equivalents, so the speed and width are checked against the figures printed in the unit system you work in. EN 115-1 also sets 30 degrees, but allows up to 35 degrees where the rise is 6 m or less and the speed is 0.5 m/s or less; its speed limit is 0.75 m/s at up to 30 degrees and 0.5 m/s above that, and its nominal width runs from 580 mm to 1100 mm. ## 10. Escalator capacity calculator: persons per hour Page: https://elevatorcalc.com/calculators/escalator-capacity MCP tool: escalator_capacity Status: First build: the code limits used here await a trade check against a licensed copy of the cited edition. Theoretical escalator capacity in persons per hour from speed and your persons per step planning input, the capacity you plan to use, and how many escalators a demand needs, with the speed checked against ASME A17.1/CSA B44 or EN 115-1. Inputs (SI; any input left out takes its default; values outside the range are refused): - standard (Code): one of "asme" (ASME A17.1-2019/CSA B44-19), "en" (EN 115-1:2017); default "asme". The escalator code the job is built to. - stepWidth (Nominal step width): one of "600" (600 mm (about 24 in)), "800" (800 mm (about 32 in)), "1000" (1000 mm (about 40 in)); default "1000". Width shown in the drawing only. It does not set the persons per step input. - personsPerStep (Persons per step (planning input)): number in , 0.1 to 4, default 1. Your assumed average occupancy per step (estimate). One person per step is a conservative starting value, independent of width. Set this editable input from your planning evidence. - speed (Rated speed): number in metres per second (m/s), 0.2 to 1, default 0.5. Speed along the incline. - demand (Peak demand in one direction): number in count, 0 to 100000, default 6000. Persons per hour you expect at the busiest time; 0 to skip the sizing. - planningShare (Planning share of the theoretical capacity): number in , 0.2 to 1, default 0.75. The fraction of the theoretical figure you count on: 0.75 means 75 percent (estimate). - units (System the code limits are checked in): one of "si" (Metric (the SI figures A17.1 prints)), "us" (US (the inch-pound figures A17.1 prints)); default "si". ASME A17.1/CSA B44 prints each limit in both systems and the two are not exact equivalents (1.0 m/s against 200 ft/min); a value is checked against the figure printed in this system, so pass "us" when the job works in US units. Inputs stay in SI units either way. The page sets this from its unit switch. Outputs: - theoreticalCapacity (Theoretical capacity (persons an hour)), count: Every step filled, rounded down. - escalatorsNeeded (Escalators needed for the demand), count: In one direction, at your planning share; 0 when no demand is given. - planningCapacity (Capacity you plan on (persons an hour)), count: Theoretical capacity times your planning share, rounded down. - capacityPer5Min (Theoretical persons in 5 minutes), count: The hourly figure divided by 12, rounded down. - demandShare (Demand as % of one escalator's theoretical capacity), : Above 100 means one escalator cannot carry the demand even when full. - personsPerStep (Persons per step counted), : Your persons per step planning input, independent of width, echoed at its entered precision. - withinLimits (Speed within the code limit), text: yes when the speed check passes. Formulas: - Steps an hour: n_s = 3600 v / s, s = 0.4 m - Theoretical capacity: C_t = 3600 v k / s, k is your persons per step planning input - Planned capacity and units needed: n = ceil(D / (phi C_t)) Basis (clause and edition): - EN 115-1-2017, Informative annex on escalator capacity; 5.2.3: Theoretical capacity from speed, step depth and persons per step; nominal speed - ASME A17.1/CSA B44-2019, 6.1.4.1: Escalator rated speed Worked example: 2 persons per step entered at 0.5 m/s, ASME, 6000 persons an hour. Input {"standard":"asme","personsPerStep":2,"speed":0.5,"demand":6000,"planningShare":0.75} gives {"theoreticalCapacity":9000,"capacityPer5Min":750,"planningCapacity":6750,"escalatorsNeeded":1,"demandShare":66.7,"personsPerStep":2,"withinLimits":"yes"}. ### How many people a step band can carry An escalator is a moving belt of steps. At a speed v, a new step arrives at the landing every s / v seconds, where s is the step depth, taken as 0.4 m for capacity. That is 3600 v / s steps an hour. Enter the average number of persons you assume on each step as a planning input. This calculator stores no width to occupancy table. Multiplying steps an hour by your input gives the theoretical capacity: with an explicit input of 2 persons per step at 0.5 m/s, it is 9000 persons an hour. ### Why plan on less People do not fill every step. They leave a step or two between groups, slow down at the comb plate, and stand to one side. Observed flows are well below the theoretical figure, so the calculator asks what share of it you count on and sizes the number of escalators from that. ### Speed limit checked A faster escalator carries more, but the codes cap the speed. ASME A17.1/CSA B44 allows 0.5 m/s (100 ft/min), and EN 115-1 allows 0.75 m/s at an angle of 30 degrees or less. The speed is checked against the figure printed in the unit system you work in. ## 11. Elevator counterweight and balance calculator Page: https://elevatorcalc.com/calculators/elevator-counterweight MCP tool: elevator_counterweight Status: Textbook statics with no code limit, so no trade check is pending for this calculator. Counterweight mass from the empty car mass, the rated load and the balance ratio, with the out of balance empty and full and the largest out-of-balance force the machine holds. Inputs (SI; any input left out takes its default; values outside the range are refused): - carMass (Empty car mass): number in kilograms (kg), 100 to 20000, default 1200. Car, sling, platform, car door and everything else that travels with the car, with no load. - ratedLoad (Rated load): number in kilograms (kg), 50 to 13500, default 1600. The load the car is rated to carry. - balance (Balance ratio): number in , 0.25 to 0.75, default 0.45. Share of the rated load the counterweight balances, as a fraction: 0.45 means 45 percent. The typical 0.40 to 0.50 range is provisional, pending trade or textbook confirmation. Outputs: - counterweightMass (Counterweight mass), kilograms (kg): Empty car mass plus the balance ratio times the rated load. - balancedLoad (Car load at balance), kilograms (kg): The load in the car at which the car and the counterweight weigh the same. - unbalanceEmpty (Out of balance, car empty), kilograms (kg): How much heavier the counterweight side is with the car empty. - unbalanceFull (Out of balance, car fully loaded), kilograms (kg): How much heavier the car side is with the rated load in the car. - maxUnbalance (Largest out of balance), kilograms (kg): The larger of the two figures above. - maxUnbalanceForce (Largest out-of-balance force), kilonewtons (kN): The largest out of balance times standard gravity: the static force the brake and the traction must hold. Formulas: - Counterweight mass: W = P + q Q - Out of balance, car empty: U_0 = q Q - Out of balance, rated load in the car: U_Q = (1 - q) Q - Largest out-of-balance force: F = g max(U_0, U_Q), g = 9.80665 m/s² Basis (clause and edition): - Traction elevator statics (textbook balance-ratio method): Counterweight mass and out of balance from car mass, rated load and balance ratio Worked example: 1200 kg car, 1600 kg rated load, balance 0.45. Input {"carMass":1200,"ratedLoad":1600,"balance":0.45} gives {"counterweightMass":1920,"balancedLoad":720,"unbalanceEmpty":720,"unbalanceFull":880,"maxUnbalance":880,"maxUnbalanceForce":8.63}. ### What the counterweight does A traction elevator hangs the car on one side of the drive sheave and a counterweight on the other. The counterweight carries the weight of the empty car plus a share of the rated load, so the motor only has to lift the difference. That share is the balance ratio. With a balance ratio q, the counterweight mass is W = P + qQ, where P is the empty car mass and Q is the rated load. The car and the counterweight balance when the load in the car is qQ. ### Out of balance, empty and full With the car empty, the counterweight side is heavier by qQ. With the rated load in the car, the car side is heavier by (1 − q)Q. The larger of the two is what the brake, the traction and the machine have to hold, so a ratio of 0.5 gives the smallest worst case. The typical 0.40 to 0.50 range is provisional, pending trade or textbook confirmation; passenger cars spend much of their time part loaded. ### What it leaves out The hoist ropes, the travelling cable and any compensation move weight from one side to the other as the car travels, and they are not included. No code clause sets the balance ratio, so none is cited; the derivation is in the calculator's spec file. ## 12. Elevator hoist rope safety factor calculator Page: https://elevatorcalc.com/calculators/elevator-rope-safety-factor MCP tool: elevator_rope_safety_factor Status: First build: the code limits used here await a trade check against a licensed copy of the cited edition. Factor of safety of elevator suspension ropes from rope count, roping, breaking load, car mass, rated load and the rope hanging in the hoistway, checked against EN 81-20 or the ASME A17.1 minimum for your speed. Inputs (SI; any input left out takes its default; values outside the range are refused): - standard (Code): one of "en" (EN 81-20:2020), "asme" (ASME A17.1-2019/CSA B44-19); default "en". The elevator code the job is built to. Under ASME, enter the minimum from the code's table for your speed. - drive (Drive): one of "traction" (Traction), "drum" (Drum (positive drive)); default "traction". EN 81-20 sets a different minimum for each. - ropes (Number of ropes): number in count, 1 to 20, default 6. Separate suspension ropes. A whole number. - roping (Roping ratio): number in count, 1 to 4, default 1. 1 for 1:1, 2 for 2:1 and so on: how many runs of each rope hold the car. - breakingLoad (Minimum breaking load of one rope): number in kilonewtons (kN), 5 to 2000, default 60. From the rope maker's certificate. - carMass (Empty car mass): number in kilograms (kg), 100 to 20000, default 1200. Car, sling, platform and everything that hangs on the car ropes, with no load. - ratedLoad (Rated load): number in kilograms (kg), 50 to 13500, default 1600. The load the car is rated to carry. - travel (Travel): number in metres (m), 0 to 600, default 30.48. Bottom landing to top landing: sets how much rope hangs below the sheave. - ropeMass (Rope mass per metre): number in kilograms per metre (kg/m), 0 to 10, default 0.35. Mass of one metre of one rope, from the certificate (estimate shown). - minimumFactor (Further minimum factor (0 for none)): number in , 0 to 40, default 0. Under ASME, the figure from the code's table for your rope speed and car type. Under EN, enter the verified EN 81-50 figure for your sheaves, even if it is below the fixed minimum. With 0 the EN check is incomplete. Outputs: - factorOfSafety (Factor of safety), : Breaking strength of all the runs over the largest static load, rounded down. - requiredFactor (Minimum checked), : The larger of the EN fixed and entered minimums, or the ASME input, echoed at its entered precision. With no EN further minimum, this is only the fixed minimum and the check is incomplete; 0 for ASME with none entered. - passes (Meets the minimum), text: yes, no, incomplete check (EN further minimum absent), or no minimum entered (ASME). - staticLoad (Largest static load on the car ropes), kilonewtons (kN): Car, rated load and hanging rope, times standard gravity, rounded up. - tensionPerRun (Tension in each rope run), kilonewtons (kN): The static load shared over every run, rounded up. - ropeMassHanging (Rope hanging on the car side), kilograms (kg): Every run times the travel times the mass per metre. - ropeRuns (Rope runs), count: Ropes times the roping ratio. Formulas: - Rope runs: N = n r - Largest static load: W = (P + Q + N m' H) g - Factor of safety: f = S N / W Basis (clause and edition): - ASME A17.1/CSA B44-2019, 2.20.3: Factor of safety of suspension ropes, f = S N / W; minimum read from the code's table for the rope speed - EN 81-20-2020, 5.5.1 and 5.5.2.2: Number of suspension ropes and their minimum safety factor by drive and rope count Worked example: Six 60 kN ropes at 1:1, 1200 kg car, 1600 kg load, 30 m travel, EN traction. Input {"standard":"en","drive":"traction","ropes":6,"roping":1,"breakingLoad":60,"carMass":1200,"ratedLoad":1600,"travel":30,"ropeMass":0.35,"minimumFactor":0} gives {"factorOfSafety":12.82,"requiredFactor":12,"staticLoad":28.08,"tensionPerRun":4.68,"ropeMassHanging":63,"ropeRuns":6,"passes":"incomplete check"}. ### What the factor of safety measures The ropes that hold an elevator car are sized with a large margin over the load they carry. The factor of safety is that margin: the breaking strength of all the rope runs together divided by the heaviest static load they hold. The heaviest static load comes with the rated load in the car at the bottom landing, where the most rope hangs below the drive sheave. It is the car, the load and that hanging rope, times gravity. With 2:1 roping each rope passes down to the car and back up, so twice as many runs share the load. ### Minimums under each code EN 81-20 asks for at least two ropes and a factor of at least 12 for a traction drive with three or more ropes, 16 for a traction drive with two, and 12 for a drum drive. It also asks for at least the figure EN 81-50 gives for the sheaves and pulleys the rope bends over; enter that verified figure even if it is below the fixed minimum. With none entered, a failed fixed-minimum or rope-count check still gives no; otherwise the overall check is incomplete. ASME A17.1 writes the factor as f = S N / W, with S the rated breaking strength of one rope, N the number of runs and W the largest static load on the car ropes. Its minimum rises with the rope speed and differs for passenger and freight elevators, and it is set by a table this site does not reproduce, so you enter the figure for your speed.