Ape Index Calculator
Compare your arm span to your height to discover your Ape Index and your unique athletic biomechanical advantages.
The Biomechanics of the Ape Index
What is the Ape Index?
The Ape Index, sometimes called the Gorilla Index or wingspan-to-height ratio, is a measure used in anatomy and sports science to describe the ratio of an individual's arm span relative to their standing height.
According to classical proportions (like Leonardo da Vinci’s Vitruvian Man), the average human arm span exactly matches their height, giving a ratio of 1.0, or a difference of 0 inches. However, millions of people naturally deviate from this, granting them unique physiological advantages.
The Positive Ape Index Advantage
A Positive Ape Index means your arm span is longer than your height. In many elite sports, this is a highly sought-after anatomical trait:
- Swimming: Elite swimmers typically have a massively positive Ape Index. Michael Phelps, for example, is 6'4" (193 cm) tall but has a wingspan of 6'7" (201 cm). Long arms act like massive paddles, displacing more water per stroke.
- Rock Climbing: Long arms allow climbers to reach distant holds while maintaining a low center of gravity.
- Combat Sports: In boxing and MMA (like Jon Jones or Conor McGregor), a longer wingspan means you can hit your opponent without entering their striking range.
The Negative Ape Index Advantage
A Negative Ape Index means your arm span is noticeably shorter than your height. While often jokingly referred to as a "T-Rex" index, it provides massive mechanical leverage in strength sports:
- Powerlifting (Bench Press): Having shorter arms means the barbell has a significantly shorter distance to travel to complete a literal rep. This is a massive mechanical advantage that allows athletes to lift vastly heavier weights.
- Gymnastics: Shorter levers make complex rotational maneuvers and strict bodyweight holds (like the Iron Cross) far easier on the shoulder joints.
Accuracy & Measurement
To get the most accurate result, stand flat against a blank wall and spread your arms entirely parallel to the floor. Have a partner measure from the tip of your longest finger on one hand, straight across the back of your shoulders, to the tip of your longest finger on the other hand.