Ape Index Calculator
Measure your ape index - how your arm span compares to your height. Enter height and wingspan in the same units (inches or cm) to get the difference (wingspan minus height), the wingspan-to-height ratio, and whether it is positive or negative.
Example: with Height 70 · Wingspan (fingertip to fingertip) 72 · Units inches → Ape index (wingspan - height): +2.0 in.
- Wingspan-to-height ratio1.029 (wingspan ÷ height)
- ReadingPositive — reach exceeds height (prized in climbing, boxing, swimming)
Computed by the calculator below using its default values. Change any input to see your own numbers.
Ape index is wingspan minus height. Zero means your arm span equals your height; a positive number means your reach is longer than you are tall.
What ape index means
Ape index compares your arm span (wingspan) to your height. Measure your wingspan fingertip to fingertip with arms stretched horizontally, then subtract your height. For most people the two are within an inch of each other, so a typical ape index is near zero. A positive index means your arms are proportionally long; a negative one means they are shorter than your height.
The name comes from the fact that apes have arm spans well beyond their height. In humans the spread is much smaller, but even a couple of inches of positive index is a real advantage in sports where reach matters.
Where a long reach helps
Rock climbers prize a positive ape index because it lets them span between holds. Boxers with longer reach can land while staying outside an opponent's range, and swimmers get more distance per stroke. In basketball, coaches often care more about wingspan than height for defense, which is why the NBA combine measures it - players there average a few inches of positive index. It is a fixed trait you cannot train, but knowing yours helps you understand your leverage in these sports.
How it’s calculated
Ape index (difference method) = wingspan - height, in whatever matching unit you enter. The ratio method = wingspan / height, where 1.0 means they are equal. Enter both measurements in the same unit (inches or centimeters).
Wingspan should be measured fingertip to fingertip with arms held horizontal. Small measurement errors shift the index by an inch or more, so measure carefully against a wall.
Ape index in different sports
| Group | Typical ape index |
|---|---|
| General population | Near 0 (wingspan approximately height) |
| NBA players (combine) | About +4 to +5 in |
| Elite boxers | Often positive; long reach prized |
| Competitive climbers | A small positive helps |
| Olympic swimmers | Frequently positive |
General guide, not strict cutoffs. NBA combine data shows wingspan averaging a few inches over height. Individual variation is large.
Common mistakes
- Measuring height and wingspan in different units before subtracting.
- Slouching or bending the arms when measuring wingspan, which shortens it.
- Treating ape index as trainable; it is a fixed skeletal proportion.
- Confusing the difference method (inches) with the ratio method (near 1.0).
Frequently asked questions
What is the ape index formula?
Ape index = wingspan - height, measured in the same units. A wingspan of 72 inches with a height of 70 inches gives an ape index of +2 inches.
What is a good ape index?
Zero is average, meaning your reach equals your height. A positive index (arms longer than height) is an advantage in climbing, boxing and basketball; negative is a slight disadvantage in those sports.
Is ape index the same as the wingspan-to-height ratio?
They describe the same thing differently. The difference method gives inches or centimeters; the ratio method divides wingspan by height, where above 1.0 means positive.
Can I change my ape index?
No. It reflects your skeletal proportions, which are fixed in adulthood. You can only measure it accurately, not train it.
How do I measure my wingspan?
Stand with your back to a wall, arms stretched out horizontally, and measure fingertip to fingertip. Keep your arms straight and level for an accurate number.