Ape Index Calculator
Calculate your ape index — the difference between arm span and height. A positive ape index is advantageous in climbing, swimming, and basketball.
Reviewed October 7, 2026 Runs in your browser — inputs are never stored
This tool provides general sports and fitness estimates for educational purposes only. It is not medical advice — consult a physician before starting or intensifying training, especially if you have a cardiovascular condition.
About the Ape Index Calculator
The ape index calculator compares your arm span with your height. A positive ape index — arms longer than you are tall — gives extra reach, which helps in climbing, swimming, basketball and combat sports. Most people have a ratio close to 1.0.
How to use it
- 1Choose centimetres or inches.
- 2Enter your height.
- 3Measure your arm span fingertip to fingertip and press Calculate.
Worked example
a height of 180 cm and an arm span of 185 cm give an ape index of +5 cm and a ratio of about 1.03.
How it works
Formula
Ape Index = Arm Span − Height (absolute method). Ratio = Arm Span ÷ Height.
Common use cases
- Climbing and bouldering
- Combat sports reach comparisons
- Swimming and basketball scouting
Frequently asked questions
A:Ape index = Arm Span − Height (absolute) or Arm Span ÷ Height (ratio). Positive means arms are longer than height.
A:Yes — in climbing, swimming, basketball, and boxing, longer reach relative to height is beneficial.
A:Michael Phelps' arm span is reportedly 201 cm with a height of 193 cm — a +8 cm ape index.
A:Most people have an ape index near 0 (arm span roughly equal to height). The average is slightly positive (+1 cm).
A:No — arm span is determined by genetics and cannot be significantly changed through training.
Reviewed for accuracy · Last updated October 7, 2026
Formulas follow published sports-science literature and official league definitions (Karvonen heart rate reserve, Cooper and Bruce protocols, MET compendium values, and standard baseball, cricket, and basketball statistics).
CalcWisee Editorial Team
Calculator development and formula review
CalcWisee is an independent site founded by Ayman. Every calculator is built from a published formula or official definition, tested against hand-worked examples before it goes live, and corrected promptly when a reader reports an issue to ayman@calcwisee.com.
Expertise: Financial mathematics, Health and fitness formulas, Applied mathematics, Unit conversion standards
References & sources