Lifting Gear Safety Factor Calculator

Work out lifting gear safety factor instantly with clear inputs, formula shown and shareable results.

About Lifting Gear Safety Factor Calculator

Working load limit is minimum breaking load divided by a safety factor set by the type of gear: four for chain, five for wire rope, seven for fibre webbing and ten for man-riding applications. The higher factors for textile slings reflect their vulnerability to cutting, abrasion and ultraviolet degradation.

Formulas

Safety factor

Factor = minimum breaking load / working load limit

Permitted WLL

Maximum WLL = minimum breaking load / required factor

Worked example

With the default values below, Lifting Gear Safety Factor Calculator returns Actual safety factor of 5.000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Minimum breaking loadminimum 0.1 kN: 80 kN
Working load limitminimum 0.1 kN: 16 kN
Type of lifting gearone of Chain sling — factor 4, Wire rope sling — factor 5, Fibre webbing sling — factor 7: Wire rope sling — factor 5

Results

Actual safety factor: 5.000
Required safety factor: 5.0
Maximum working load limit permitted: 16.00 kN
Compliance: Safety factor meets the requirement for this gear type

Step by step

1Values used
2Safety factor
3Permitted WLL
4Actual safety factor= 5.000
5Required safety factor= 5.0
6Maximum working load limit permitted= 16.00 kN
7Compliance= Safety factor meets the requirement for this gear type

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Preliminary estimate only. Lifting equipment ratings, examination and certification must follow the applicable regulations and the manufacturer's data.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Preliminary estimate only. Lifting equipment ratings, examination and certification must follow the applicable regulations and the manufacturer's data.

Frequently Asked Questions

How is the Lifting Gear Safety Factor figure worked out?

Factor = minimum breaking load / working load limit. Working load limit is minimum breaking load divided by a safety factor set by the type of gear: four for chain, five for wire rope, seven for fibre webbing and ten for man-riding applications.

Why does man riding need a factor of ten?

Because a failure is immediately fatal and the consequences justify a much larger margin against the unknowns of wear, shock loading and inspection interval.

What values do I need to enter?

This calculator takes 3 inputs: Minimum breaking load, Working load limit, Type of lifting gear. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.