Stand in your stocking feet with your back flat against a wall.
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Make sure you use the same units of measurement (feet, inches, centimeters or meters) that you used to measure your reach.
 If the result is greater than 1 your reach is longer than your height, which is also known as having a positive ape index.



If the result is positive, your reach is longer than your height. This is usually expressed as a positive ape index, or a +1, +2, or so on ape index, with the number expressing the number of units your reach is longer than your height. (So a person with a +1 ape index might have a reach that is 1 inch (2.5 cm) longer than his height.
A "negative ape index" is expressed similarly, but with a minus or negative sign instead of the plus.
Measure your height.
Ask your friend to make a mark on the wall, level with the top of your head.

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Step away from the wall and help your friend measure straight up from the floor to the mark, to get your height.
Divide your reach measurement by your height to express your arm span as a ratio.
Subtract your height measurement from your reach measurement to get a more concrete "ape index" result.
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