Last updated: 3 October 2026
Reviewed by Jordan Morley, FA Level 2 Football Coach
Ape index = arm span − height. A positive ape index means your arms are longer than your height, giving a reach advantage on longer moves. This is advantageous for climbing because you can reach higher holds without as much body positioning. Many elite climbers have positive ape indexes of +5 to +10cm. Adam Ondra, the first person to climb 9c, has an ape index of approximately +8cm. However, climbers with negative ape indexes compensate with superior technique and hip mobility.
- Arm span minus height
- Positive = reach advantage
- Elite climbers often +5 to +10cm
- Technique compensates for negative index
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A positive ape index (arm span longer than height) is generally seen as an advantage in climbing because it lets a climber reach further holds without repositioning their feet, though technique, finger strength and body tension matter far more than this single measurement — many elite climbers have a neutral or even negative ape index.
FAQ
What's considered a 'good' ape index for climbing?
Anything positive (arm span exceeding height) is considered advantageous, though the effect is modest compared to skill, strength and technique.
Can ape index predict climbing ability?
No — it's a minor physical trait among many; technique, finger strength, core tension and route-reading ability matter far more than reach alone.