Calculate your ape index to discover your climbing and athletic potential. Compare your arm span to your height.
Enter your height in centimeters (50-300 cm)
Measure fingertip to fingertip with arms spread (50-300 cm)
Fill in your height and arm span to calculate your ape index and discover your athletic potential.
Arms longer than height (>+5 cm). Common in climbers, swimmers, and basketball players. Provides reach advantage and better leverage.
Arms and height are nearly equal (-5 to +5 cm). Most common in the general population. Balanced proportions suitable for various sports.
Arms shorter than height (<-5 cm). May benefit gymnastics and weightlifting. Lower center of gravity, better stability in certain movements.
Your ape index is the difference between your arm span and your height. It tells you if your arms are longer, shorter, or about equal to your height. Rock climbers, swimmers, and basketball players pay close attention to this measurement because it affects how they move and perform.
The name comes from apes and primates, who have much longer arms than humans. Gorillas can have an ape index of +30 cm or more. For humans, most people have an ape index close to zero (your arm span roughly equals your height). But some folks are built differently.
Athletes with positive ape indexes (longer arms) often excel in sports requiring reach. Think Michael Phelps with his +8 cm advantage, or NBA players who can grab rebounds over taller opponents. Climbers with longer arms can reach holds that others can't, giving them a real edge on difficult routes.
This measurement matters beyond sports too. Physical therapists use it to assess body proportions. Clothing manufacturers consider it for better fits. Even doctors look at arm span when height measurements aren't reliable (like for people with spinal issues).
The ape index calculator gives you two numbers: the absolute difference (in centimeters) and the ratio (arm span divided by height). Both tell the same story, just in different ways. A positive index means longer arms, negative means shorter arms, and neutral means they're about even.
Using the ape index calculator is simple. You'll need two measurements: your height and your arm span. Here's how to get accurate results:
Pro tips for accuracy: Measure in the morning when you're tallest (you compress during the day). Keep your arms perfectly horizontal when measuring wingspan. Don't stretch or lean. Have someone help you measure for better accuracy. Take three measurements and use the average.
Common mistakes to avoid: Don't measure with shoes on. Don't pull your shoulders back or forward. Don't bend your elbows. Make sure the tape measure is straight and level. These small errors can throw off your ape index by several centimeters.
The ape index calculation is straightforward math. You're comparing two body measurements to see how they relate.
Ape Index = Arm Span - Height
This gives you the difference in centimeters. A positive number means longer arms. A negative number means shorter arms.
Ape Index Ratio = Arm Span ÷ Height
This gives you a ratio. A value of 1.0 means equal proportions. Above 1.0 means longer arms. Below 1.0 means shorter arms.
Example 1: Positive Ape Index
Height: 175 cm | Arm Span: 182 cm
Ape Index = 182 - 175 = +7 cm
Ape Index Ratio = 182 ÷ 175 = 1.040
This person has arms 7 cm longer than their height. Great for climbing and swimming.
Example 2: Neutral Ape Index
Height: 168 cm | Arm Span: 169 cm
Ape Index = 169 - 168 = +1 cm
Ape Index Ratio = 169 ÷ 168 = 1.006
Nearly equal proportions. This is typical for most people.
Example 3: Negative Ape Index
Height: 180 cm | Arm Span: 172 cm
Ape Index = 172 - 180 = -8 cm
Ape Index Ratio = 172 ÷ 180 = 0.956
Arms shorter than height. May benefit gymnastics and powerlifting.
Why does this work? Human body proportions follow patterns. Leonardo da Vinci's Vitruvian Man showed that arm span typically equals height. But genetics, ethnicity, and individual variation create differences. The ape index quantifies those differences in a simple number.
Your ape index number tells a story about your body proportions. Here's how to understand what your results mean.
>+5 cm
Arms longer than height. About 30% of people have this. Common in athletes who need reach (climbers, swimmers, basketball players).
-5 to +5 cm
Balanced proportions. About 50% of people fall here. Your arm span roughly equals your height. This is the human average.
<-5 cm
Arms shorter than height. About 20% of people have this. May benefit sports needing compact builds (gymnastics, weightlifting).
Professional athletes often have extreme ape indexes. Michael Phelps (+8 cm) used his reach to dominate swimming. NBA players average +4 to +7 cm, giving them rebounding advantages. Elite rock climbers often exceed +10 cm, reaching holds others can't.
But a high ape index doesn't guarantee athletic success. Technique, strength, and training matter more. Plenty of world-class athletes have neutral or even negative ape indexes. Use your results to understand your natural advantages, not as limitations.
Your ape index is just one measurement. It doesn't define your athletic potential or worth. People with all types of proportions succeed in sports and life. This calculator simply helps you understand your body's natural build.
Your ape index can give you natural advantages in certain sports. Here's how different measurements play out.
Rock Climbing
Longer arms mean you can reach distant holds without jumping or stretching as much. This saves energy and opens up routes that shorter-armed climbers can't do. Elite climbers often have +8 to +15 cm ape indexes.
Swimming
Greater arm span creates more surface area for pulling through water. Each stroke covers more distance. Michael Phelps's +8 cm gave him a measurable advantage in freestyle and butterfly.
Basketball
Longer arms help with rebounding, blocking shots, and stealing passes. You can reach the basket easier and contest shots from further away. Most NBA players have positive ape indexes and shooting efficiency that benefits from their reach advantage.
Boxing and MMA
Greater reach lets you hit opponents while staying outside their range. Jon Jones (UFC) has an exceptional +13 cm ape index, giving him a massive striking advantage. Combined with punch force, longer arms can generate more knockout power through increased leverage.
Gymnastics
Shorter arms relative to height create better leverage for holds and swings. You're more compact, making rotations faster. Many elite gymnasts have neutral or slightly negative ape indexes.
Powerlifting
Shorter arms mean less distance to move the weight. Bench press and deadlift both benefit from compact arm proportions. Many record holders have negative ape indexes.
Sprinting
Shorter limbs relative to torso can improve stride efficiency. Less momentum waste from arm swing. Many elite sprinters have neutral to slightly negative proportions.
Remember, these are tendencies, not rules. Plenty of successful athletes have "wrong" proportions for their sport. Training, technique, and mental toughness beat body measurements every time. Your ape index just tells you where you might have a natural edge.
The ape index calculator is useful, but it has limits. Here's what it can't tell you and when you need expert advice.
Talk to a doctor if you notice:
For athletic training, work with a coach who can assess your whole body, not just arm length. They'll evaluate strength, flexibility, technique, and mental aspects. Your ape index is one tiny piece of a much bigger puzzle.
This calculator is for informational and entertainment purposes. It's not medical advice. Don't use it to diagnose conditions or make health decisions. If you have concerns about your body proportions or physical development, consult a healthcare provider.
Ape index is just one way to look at body proportions. Here are related measurements that athletes and researchers use.
This compares your sitting height to your total height. It tells you if you have a long torso and short legs, or vice versa. Two people with the same ape index can have very different sitting height ratios. Cyclists and rowers care about this because torso length affects their positions and power output.
The ratio of leg length to total height. Long legs help with running and jumping. Short legs help with squatting and stability. This matters more for some sports than ape index does.
Wide shoulders combined with long arms create the ideal swimmer's build. Shoulder width matters for overhead sports like volleyball and tennis. You can't change your arm length, but you can build shoulder muscle.
Hand span and finger length matter for basketball, climbing, and catching sports. Some climbers with shorter arms compensate with larger hands that can grip holds better.
The takeaway? Your body is complex. Ape index gives you one piece of information. Don't obsess over it. Focus on developing the body you have through smart training.
Most elite climbers have ape indexes between +5 and +15 cm. But you can climb at a high level with any ape index. Technique, finger strength, and mental game matter more than arm length. Don't let your measurements discourage you from trying climbing.
No. Your bone lengths are fixed after you stop growing (usually late teens to early twenties). You can't make your arms longer or shorter through exercise. What you can change is your strength, flexibility, and how you use your proportions.
Different calculators might round numbers differently or use slightly different classification ranges. Small measurement errors add up too. If you measured 175.3 cm and rounded to 175, but another time you rounded to 176, your ape index changes by 1 cm. This is normal.
Men average slightly longer arms relative to height compared to women. But there's huge overlap. Plenty of women have higher ape indexes than the male average. Gender affects the average, not the range.
Keep your arms straight but relaxed. Don't hyperextend your elbows or pull your shoulders back. Just let your arms hang naturally in a horizontal position. Tension or bending can change your measurement by 2-3 cm.
Yes. Wingspan, arm span, and reach are all the same measurement. It's the distance from fingertip to fingertip when your arms are spread horizontally. Some sports use different terms but they mean the same thing.
Yes. Marfan syndrome causes unusually long limbs and high ape indexes. Achondroplasia causes shorter limbs. Most people don't have these conditions. If you have an extremely unusual ape index (beyond ±15 cm) and other symptoms, see a doctor. But for most folks, variation is just normal genetics.
Once you're done growing (usually by age 21), your ape index won't change. You can remeasure if you want to check your accuracy, but the number stays the same throughout adult life. Your bones don't shrink or grow unless you have a medical condition.