Ape index calculator
Enter your height and reach to see your ape index, your reach-to-height ratio and what it means.
What is the ape index?
Your ape index is the difference between your arm span, also called reach, and your height. If you are 178 cm tall and your fingertip-to-fingertip span is 183 cm, your ape index is +5 cm. The term comes from climbing, where long arms relative to height are useful, and it is now common in MMA, boxing and basketball. Some people prefer the ratio, reach divided by height, which makes the number comparable between tall and short athletes. This calculator shows both.
How to measure yourself properly
Stand with your back against a wall and raise both arms out to the sides at shoulder height, palms forward. Have a friend measure from the tip of one middle finger to the tip of the other, keeping the tape level. Then measure your height barefoot against the same wall. Measure twice and average the results, because small errors of one or two centimetres change the answer noticeably. Official fight reach figures are recorded in a similar way, but they are not always measured under identical conditions, so treat them as close estimates.
How to read your result
Most adults have a reach close to their height, so a ratio near 1.00 is normal. As a rule of thumb used in this tool, a ratio from about 0.97 to 1.03 is considered typical. Above that, you have longer-than-average arms for your height. Below it, you have shorter arms. These bands are a general guide, not a scientific standard, and they vary by population, age and sex. A positive ape index is not a guarantee of success. Technique, timing, conditioning and fight IQ still do most of the work.
Why reach matters in MMA
A longer reach can let a fighter land strikes from outside the opponent's range, use the jab and teep to control distance, and defend takedowns with long frames. It can also help with submissions such as the triangle and armbar, where leverage is key. But long limbs bring trade-offs. They can be easier to catch and trap in clinches, and they can make body positioning harder on the ground. Read the full discussion in Ape index in MMA: what it means and why it matters and what reach means in MMA.
Comparing your number with fighters
You can look up real fighters in the comparison tool and work out their ratios by switching units and using the height and reach rows. Keep in mind that published figures are rounded and sometimes disputed. A fighter listed with a three-inch positive ape index might be measured at two or four inches on another day. Use the results to understand the idea, not to rank athletes down to the centimetre.
Limits of the calculator
The tool only does arithmetic on the two numbers you enter, and it assumes both are measured correctly. It does not account for shoulder width, hand size or arm length distribution, which also affect real reach. It is meant for education and curiosity, not for diagnosing anything about your body or predicting athletic performance.
Frequently asked questions
What is a good ape index?
There is no single good number. A ratio near 1.00 is typical, and many fighters have a modest positive index. What matters is how well you use your reach.
Is ape index the same as reach?
No. Reach is your arm span. Ape index is reach minus height, or the ratio of reach to height.
Can I use inches?
Yes. Switch the unit toggle to inches and enter both measurements in inches.
Does a long reach win fights?
Not by itself. It helps with distance control, but timing, wrestling and cardio decide many fights.
How accurate are fighter reach numbers?
Published reach figures are estimates and can differ between sources.