RopeFactor Wire-rope verification sheet Open the calculator
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Elevator suspension-rope calculations, with every step shown.

RopeFactor is a calculation tool for traction elevator suspension ropes. It checks factor of safety, traction, estimated rope life, elongation, rope dynamics, groove pressure and rope order lengths. Each report gives the inputs, formula, substituted values, result and reference for every check, so the calculation can be reviewed independently.

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Free during beta. An email address and acknowledgement of the beta notice are required to enter.

A 1:1 overhead traction arrangement: ropes pass over a single drive sheave with the car hanging on one side and the counterweight on the other, labelled with the car-side tension T1, the counterweight-side tension T2, and the traction sheave diameter Dt. Dt T₁ T₂ CAR
1:1 overhead, as in the worked example.

What it calculates

Factor of safety

Calculates the required and actual factor of safety, rope load as a percentage of minimum breaking force, and the drive sheave-to-rope diameter ratio.

ISO 8100-2:2026 §4.12 · ASME A17.1-2022 §2.20.3 + Table 2.20.3

Traction

Calculates the friction factor from the groove geometry, then compares available traction efα against the requirement for normal loading, emergency braking and stalled-car conditions.

ISO 8100-2:2026 §4.11 · §4.13.6

Rope life

Estimates bending fatigue from the traction sheave, simple bends and reverse bends, combined by Palmgren-Miner accumulation. Reports 10th-percentile and mean service life.

Feyrer, Wire Ropes (2nd ed.)

Elongation

Estimates elastic elongation at rated load and constructional stretch, from rope construction and modulus.

EN 12385-2 / ISO 17893 area factor

Rope dynamics

Calculates lateral and longitudinal rope frequencies over the full travel and checks for crossings with sheave excitation frequencies.

Resonance screening only

Groove pressure

Calculates specific groove pressure for U, undercut-U and V grooves. Reported for comparison of rope and groove loading.

No code acceptance limit applies

Rope data

RopeFactor includes published rope data from ISO and ASME sources. A specific rope can also be entered from the manufacturer's certificate.

ISO catalogue

39 rope constructions from ISO 4344:2022 — 6-, 8- and 9-strand ropes with fibre, IWRC, PWRC and compound cores. Published minimum breaking force factors, rope mass and metallic area are included.

ISO 4344:2022 Annex C / Annex D

ASME catalogue

848 rope entries from the nine tables in ASME A17.6-2022 Mandatory Appendix I. Selectable by diameter, construction and grade, from Iron through Extra Improved Plow Steel.

ASME A17.6-2022 Mandatory Appendix I (I-1-1 … I-1-9)

Custom ropes

Enter a rope from its certificate: construction, core, diameter, minimum breaking force, mass and grade. Saved ropes stay in your browser and can be reused on later calculations. A rope schedule can be imported from CSV, and the library exported for use on another computer. Saved rope data is stored in SI units and converted automatically on an imperial project.

Required for rope life, elongation, dynamics and groove pressure

A catalogue rope carries a published breaking force, which is sufficient for the factor of safety and traction checks. Rope life, elongation, dynamics and groove pressure require the rope's own mass and construction, so those calculations need a rope entered from its certificate.

The report

A page from a RopeFactor report showing the ISO 8100-2 safety-factor derivation: the sheave-to-rope diameter ratio, the equivalent pulley and traction deflections, per-rope tension, Formula (36) with its values substituted, the governing minimum, the computed safety factor of 16.96 and a PASS verdict, each row citing its clause.
Factor-of-safety page from the ISO example, one of eleven. Download the full report (PDF).

The report shows the formula, substituted values, result, units and reference for each calculation. This allows the calculation to be reviewed without reopening the project in RopeFactor.

For example, the required ISO factor of safety is shown with the substitution used to obtain it:

10^(2.6834 − log10(695.85×10⁶ × N_eq ÷ (Dt/dr)^8.567) ÷ log10(77.09 × (Dt/dr)^−2.894)) = 13.8848

The terms and the clause are set out under ISO factor of safety.

  • Metric or imperial units, based on the selected code.
  • A reeving diagram based on the entered arrangement.
  • Calculation assumptions and limitations where applicable.
  • An optional DRAFT watermark.

Reference

Notes and worked examples covering the calculations RopeFactor performs.

Important

RopeFactor is a calculation tool. It does not provide engineering approval, and its reports are not signed or sealed. The software is in beta. Calculations should be independently reviewed and verified before they are used for design, installation or code compliance.