Editing Fall factor (section)

{{Short description|Mathematical ratio relevant to climbing safety}}
[[File:Fall factor diagram.svg|thumb|250px|The climber will fall about the same height ''h'' in both cases, but they will be subjected to a greater force at position 1, due to the greater fall factor.]]
In [[lead climbing]] using a [[dynamic rope]], the '''fall factor''' ('''''f''''') is the ratio of the height (''h'') a climber falls before the climber's rope begins to stretch and the rope length (''L'') available to absorb the energy of the fall,

:<math>f = \frac{h}{L}.</math>

It is the main factor determining the violence of the forces acting on the climber and the gear.

As a numerical example, consider a fall of 20 feet that occurs with 10 feet of rope out (i.e., the climber has placed no protection and falls from 10 feet above the [[Belaying|belayer]] to 10 feet below—a factor 2 fall). This fall produces far more force on the climber and the gear than if a similar 20 foot fall had occurred 100 feet above the belayer. In the latter case (a fall factor of 0.2), the rope acts like a bigger, longer rubber band, and its stretch more effectively cushions the fall.