Fall factor is the ratio of fall distance to the length of rope available to absorb the fall. It ranges from 0 to 2 (maximum). A fall factor of 2 means you fell the entire length of rope out plus back down again, such as falling from above the belay with no protection placed. The higher the fall factor, the greater the force on the climber and anchor.

Why is fall factor more important than fall distance?

A 2-metre fall on 2 metres of rope (factor 1.0) generates more impact force than a 10-metre fall on 30 metres of rope (factor 0.33). This is because more rope means more stretch to absorb the energy. That is why the first piece of protection above a belay is so critical.

What impact force is dangerous?

UIAA standards require dynamic ropes to hold a fall with no more than 12kN of peak impact force. Forces above 6kN can cause injuries. Most sport climbing falls with proper protection generate 2-5kN. A factor 2 fall can generate forces approaching the rope rated maximum.

How do dynamic ropes reduce impact force?

Dynamic ropes stretch 30-40% under load, absorbing fall energy gradually rather than all at once. Static ropes stretch less than 5% and should never be used for lead climbing as the impact forces would be dangerously high.

CampCalcs

Fall Factor Calculator

Calculate fall factor, impact force and energy from fall distance and rope out. Understand the severity of different fall scenarios.

Fall Distance

Total distance fallen

Rope Out

Length of rope between climber and belayer

Climber Weight

Including gear and harness

Rope Type

How We Calculate This

This calculator determines fall factor and estimates the impact force on the climber.

Fall factor formula

Fall factor = Fall distance / Rope out

Severity ratings

Low (0 - 0.3): Minor fall, gentle catch
Moderate (0.3 - 1.0): Standard lead fall
High (1.0 - 1.5): Serious fall, significant force
Very high (1.5 - 2.0): Factor 2 territory, maximum force

Impact force estimation uses a simplified rope modulus calculation. Actual forces vary with rope model, number of falls held, friction through quickdraws, and belay technique.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify conditions and use proper safety equipment outdoors.