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What’s Your Ape Index?

What’s your ape index? We explain how to find yours, and how it affects your climbing.


Your ape index – also referred to as your ape factor – is a measurement of your wingspan in ratio to your height. Most humans have a neutral ape index, or a ratio of 1, which means that the length from your fingertip to fingertip is the same as your height. Longer arms than you are tall: you’ve got a positive ape index. Shorter wingspan than how high you stand? You’ve got a negative ape index. You can figure out your own ape index by dividing your arm span by your height, or use this handy calculator.

Here at Brooklyn Boulders we have a range of positive, neutral, and negative ape indexes.

Rob Henry, our climbing assistant, stands at 6’4″ but his arms span a whopping 6’8″, giving him a positive ape index of +4:

rob henry positive

Luke Livesey, our Head of Instruction, stands at 5’7″ and his arms span about the same length, making him neutral:

luke neutral


Cyrena here, stands at 5’1″ and her arms are a short 4’10” across, resulting in a negative ape index of -3:

c neg

If you automatically assume that a positive Ape Index is the key to being good at climbing, think again. Sure, having long arms is an advantage to reach that high-up hold, but then it’s much harder to actually pull yourself up (physics, dude). Shorter arms might mean more dynamic jumps, but it also means the pull motion is much easier (I can do 13 pull-ups and counting!).

And to quote this study, “engaging in a training programme to increase muscular strength, power, and endurance is more important than flexibility and anthropometric measurements for determining climbing performance in climbers of all abilities,”.

Note: shorter people can have positive ape indexes as well. Just see BKBeasts team member Georgia for proof, who has a +4:

georgia wingspan


Keep on climbing & training!

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