APE INDEX CALCULATOR
Adam Ondra, arguably the greatest climber alive, has an ape index of +1cm. That's basically average. Calculate yours below and discover what actually predicts climbing performance.
WHAT IS THE APE INDEX?
The ape index compares your arm span to your height. It's one of the most discussed measurements in climbing, and one of the most misunderstood. Climbers debate it endlessly on forums, sometimes blame it for failed sends, and occasionally use it as an excuse to skip training. The reality is much simpler: it's a fun number to know, but it doesn't define your potential as a climber.
The concept traces back over 2,000 years to the Roman architect Vitruvius, who proposed that the ideal human body has an arm span equal to its height, a perfect 1:1 ratio. Leonardo da Vinci later immortalized this idea in his famous Vitruvian Man drawing. The term "ape index" itself was actually coined by Frisbee players at UC Berkeley in 1975, well before the climbing community adopted it.
There are two ways to express your ape index. The subtraction method (arm span minus height) gives you a number in centimeters or inches. Positive means your reach exceeds your height, negative means it's shorter. The ratio method (arm span divided by height) gives a decimal where 1.0 means they're equal. Most climbers use the subtraction method because it's more intuitive.
APE RATIO
The term ape ratio is another way of describing what climbers call the ape index. It measures the relationship between your arm span and your height, offering a quick reference for your natural reach. A positive ape ratio means your wingspan is longer than your height. Whether you call it ape index, ape ratio, or arm span to height ratio, it's the same measurement. Knowing your number can help you better understand how your body mechanics might influence your climbing style, but as we'll cover below, it's far from the most important factor in your climbing performance.
HOW TO MEASURE AND CALCULATE YOUR APE INDEX
To find your ape index, you need two measurements: your arm span and your height. Here's the most accurate way to get both.
ADVANTAGES AND DISADVANTAGES OF DIFFERENT APE INDEX VALUES
A positive ape index, where your arm span exceeds your height, is often perceived as advantageous in climbing. It can help you reach holds that shorter-armed climbers might need to jump for. On vertical and slightly overhanging terrain, extra reach is genuinely useful.
But the advantages aren't straightforward. Longer arms also mean longer lever arms, which require more shoulder strength to control. Compression-style bouldering problems, where you need to squeeze holds close to your body, can feel awkward with very long arms. And many elite climbers with neutral or even unknown ape indexes compensate through superior dynamic movement, hip flexibility, and creative beta-finding.
The bottom line: your ape index creates tendencies, not limits. Every body type has both advantages and trade-offs depending on the style of climbing.
THE VITRUVIAN MAN AND THE PERFECT RATIO
Da Vinci's Vitruvian Man proposed that the "perfect" human body has a 1:1 ratio between arm span and height. In climbing, this ideal ratio carries no specific advantage. Some of the strongest climbers in history, including Tommy Caldwell, Alexander Megos, and Hazel Findlay, have exactly this neutral ratio. Others like Alex Honnold and Kai Lightner have dramatically positive indexes. There is no "perfect" ape index for climbing.
The most comprehensive database of professional climber measurements on the internet. Notice the range: elite climbers exist at every point on the spectrum.
Magnus Midtbø Ape Index
Adam Ondra Ape Index
Alexander Megos Ape Index
Alberto Ginés López Ape Index
Tomoa Narasaki Ape Index
Alex Honnold Ape Index
Chris Sharma Ape Index
Wolfgang Güllich Ape Index
Lynn Hill Ape Index
Ashima Shiraishi Ape Index
Alex Puccio Ape Index
Janja Garnbret Ape Index
Brooke Raboutou Ape Index
Tommy Caldwell Ape Index
Nalle Hukkataival Ape Index
Daniel Woods Ape Index
Kai Lightner Ape Index
Sasha DiGiulian Ape Index
Jimmy Webb Ape Index
Paul Robinson Ape Index
Matt Fultz Ape Index
Ethan Pringle Ape Index
Dave Graham Ape Index
Jongwon Chon Ape Index
Kai Harada Ape Index
Jonathan Siegrist Ape Index
Sascha Lehmann Ape Index
Kyra Condie Ape Index
Emily Harrington Ape Index
Hazel Findlay Ape Index
Angy Eiter Ape Index
| Climber ↕ | Wingspan ↕ | Height ↕ | Ape Index ↓ | Notable Achievement |
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Climbers treat ape index like destiny. The peer-reviewed research tells a different story. Multiple studies have examined the relationship between body proportions and climbing performance, and the results are consistent.
A landmark study published in the British Journal of Sports Medicine in 2000 tested 44 climbers (24 men, 20 women) ranging from 5.6 to 5.13c. The researchers measured everything: height, arm span, grip strength, endurance, flexibility, years of experience, and training hours. After running a multiple regression analysis, they found that trainable variables (strength, endurance, experience) explained 58.9% of climbing performance. Anthropometric factors like ape index? Just 0.3%. That's not a typo.
A 2023 systematic review published in the Journal of Strength and Conditioning Research reinforced this finding after analyzing studies from 2000 to 2021. Their conclusion: ape index did not differ significantly between sport climbers of various skill levels. V4 climbers and V12 climbers have essentially the same distribution of ape indexes.
It's worth noting that the research isn't 100% one-sided. Some studies have found a weak correlation between ape index and climbing ability, particularly when comparing climbers to non-climbers. But within the climbing population, the consensus is clear: once you're climbing, your training habits and finger strength matter far, far more than your proportions.
TRAINABLE FACTORS IN CLIMBING
While the ape index provides an interesting perspective on physical attributes, climbing is a multifaceted sport where trainable factors consistently outweigh genetic advantages. Finger strength, grip endurance, technique, flexibility, and experience are the critical components that determine climbing proficiency. These factors can be developed and refined over time, giving every climber the opportunity to improve regardless of their body proportions.
Finger strength stands out as the single strongest predictor of climbing grade. Multiple studies confirm that grip strength measured on small edges correlates more strongly with climbing ability than any other physical metric, including body composition, flexibility, arm span, or height. A progressive hangboard routine is the most efficient and evidence-based method to build this strength.
Regardless of your ape index, specific training strategies can help you climb harder. Here are some general areas to focus on based on your proportions.
- Get comfortable with dynamic movement and momentum generation
- Prioritize hip flexibility for high foot placements that extend your effective reach
- Develop strong core tension for controlled reaches on steep terrain
- Look for creative beta. There's almost always a sequence that works for shorter climbers
- Build explosive finger strength for dynamic catches
- Don't rely on reach as a crutch. Develop technique and body awareness equally
- Build shoulder stability to support longer lever arms on steep terrain
- Practice compressed "scrunchy" positions that may feel awkward with long arms
- Develop lock-off strength to control your arm through full range of motion
- Train hangboard with various grip positions to maximize your reach advantage
YOUR FINGER STRENGTH WILL.
Progressive edge depths from 40mm to 10mm. Designed for every climber, from V0 to V14.
GET THE HANGBOARD — $89.99What is the ape index?
The ape index is a comparative measure of an individual's arm span relative to their height. It's commonly used in sports like climbing to discuss reach advantage. It can be calculated by subtracting your height from your arm span (giving a +/- value in cm or inches) or by dividing arm span by height (giving a ratio where 1.0 means they're equal). You can use our calculator above to find yours.
How to measure your ape index?
Measure your ape index by stretching your arms out wide and measuring the span from the tip of one middle finger to the other. Then measure your height standing barefoot. Subtract your height from your arm span. The result is your ape index: a positive number means your reach exceeds your height, a negative number means it's shorter.
What is a good ape index?
A good ape index varies depending on the sport or activity. In climbing, an index greater than 1 (where your arm span exceeds your height) is often seen as advantageous, offering a greater reach. However, many professional climbers don't have especially positive ape indexes. Adam Ondra, widely considered the greatest climber alive, has just +1cm. Tommy Caldwell and Alexander Megos both have a neutral 0cm index.
What is my ape index?
To determine your ape index, use our calculator at the top of this page or measure your arm span from fingertip to fingertip and subtract your height. The result tells you whether you have a longer reach (positive index) or shorter reach (negative index) compared to your height.
What is a high ape index?
A high ape index means your arm span is significantly longer than your height. An index greater than 1.0 is considered positive, but a high ape index would start around 1.02 to 1.03 (or roughly +4cm and above). Daniel Woods, a professional climber, has a 1.06 ape index, or +10.2cm. Kai Lightner has the highest documented among elite climbers at +17.5cm. In other sports, the NBA average is about 1.063 and Michael Phelps has approximately +10cm.
What is the average ape index?
The average ape index is typically 1.0, meaning that for most people, their arm span is equal to their height. This average can vary slightly based on population and demographics. Having an "average" ape index puts you in the same range as Adam Ondra (+1cm), who has an essentially neutral ape index and climbs the hardest routes in the world.
What is a small ape index?
A small (or negative) ape index indicates that a person's arm span is shorter than their height, with a ratio less than 1.0. This doesn't necessarily hinder overall athletic ability or climbing performance. There are many climbers at the professional level with a neutral or negative ape index who compete at the highest levels through superior technique, power, and training.
Can you improve your ape index?
No. Your ape index is determined by your skeletal proportions and cannot be changed. But that's actually good news, because research shows ape index accounts for only about 0.3% of climbing performance. Your time is much better spent improving trainable factors like finger strength, technique, and climbing experience, which account for the vast majority of what makes a good climber.
Does ape index help more in bouldering or sport climbing?
There's a slight theoretical advantage in sport climbing, where sustained reach between distant holds is more common. In bouldering, problems tend to be shorter with more compressed and dynamic movement. But in practice, elite climbers at the top of both disciplines span the full range of ape indexes, suggesting the impact is minimal in either discipline.
Ape index meaning
The ape index meaning refers to the comparison between a person's arm span and their height. The name references how apes have arm spans significantly longer than their height. A positive ape index means your wingspan is longer than your height, which can offer some reach benefits in climbing. It's also discussed in basketball, MMA, and swimming. Whether you're calling it ape index, ape ratio, or arm span to height ratio, it's the same measurement.
CONCLUSION
The ape index is a fascinating aspect of climbing physiology and a fun number to know. But it's crucial to remember that it's just one small piece of the climbing puzzle. The peer-reviewed research is clear: a balanced focus on training, skill development, and experience plays a far more significant role in a climber's journey than any body proportion. Whether your ape index is high, low, or average, the path to climbing harder lies in consistent training and genuine love for the sport.
