Ape Index Calculator

About this calculator

Ape index compares arm span to height, expressed either as the difference in centimeters (arm span minus height) or as a ratio (arm span divided by height). A positive ape index means your wingspan exceeds your height — an ape-like build — while a negative index means your height exceeds your reach, and zero means they’re equal; most people fall within a couple of centimeters of zero either way.

Rock climbers popularized the term because a longer reach relative to height is a genuine mechanical advantage for spanning holds on a route, and it’s commonly discussed in climbing communities alongside grip strength and finger strength as a factor (though far from the only one) in climbing performance. It also gets referenced in basketball scouting, where wingspan is measured separately from height to estimate a player’s effective reach on defense and rebounding, and in boxing, where a longer reach affects range in a fight.

This calculator takes your arm span and height and returns your ape index in centimeters and as a ratio.