Your ape index is the difference/ratio between your arm span and your height. I prefer the ratio method cause then we can compare apples to apples. A 4 inch difference on a 6'6" person is a lot less significant then if your 5'5". Jen prefers the difference cause it sounds better and is easier...and it's what she learned first.

It's all based of DaVinci's Vitruvian Man, the theory being that our height and armspan are identical...in reality not so much.

So in shameless self-intrest, this page lets you calculate the ratio :P

The units don't matter as long as both measurements are the same, so don't put any in. Height is floor to top of your head, arm span is fingertip to fingertip with your arms horizontal.

What does this number mean?

• A number of less than 1 means you have stubby arms.
• 1 means you are symetrical and boring. (Welcome to the club)
• A number of more than 1 means you have gangly arms.

It's thought that a higher ape index is indicative of being better at sports like swimming, or climbing, or boxing. No-one has proven or killed the theory, so take it as you will. I see it as helpful for planning how you move. Short arm swimmers can move their arms faster through the water, but push less water. So since pressure = force / area, they actually put out the same amount of energy and should (all else being equal) move at the same speed.

But doesn't it take more energy to move your arm faster in a full circle than push more water for half a circle? Not really, longer arms require more torque to push through the water, which requires more strength.

So while your ape index is amusing, you will find that technique, drive, and endurance are much more important. Go figure.