What Is the Ape Index?
Ape Index is a measurement of how a person’s arm span (a.k.a. wingspan) compares to their height. It is widely accepted that a person’s arm span is exactly the same as their height (a neutral ape index), but that’s simply not the case.
While a lot of people do have a neutral or “normal” ape index, it’s not uncommon to see a negative ape index or a positive ape index as well. Granted, the differences are small and normally only vary by as little as 1-4in, but some people can have a much higher ape index. In sports like rock climbing, swimming, boxing, and basketball, a positive ape index can be considered a natural competitive advantage.
In this article, we will be exclusively using the term ape index, but you could also refer to it as ape factor or gorilla index.
How to Calculate Your Ape Index
Method #1: Arm Span to Height Ratio
Using this method, you simply divide wingspan/height. A neutral ratio would be a 1. The larger the number, the larger your ape index, meaning your arm span is longer than your height. A number less than one is the opposite, meaning your arm span is shorter than your height. Some believe that an ape index greater than one is beneficial in many different sports.
Since it’s a ratio, the benefit of using this method is that it uses the same scale no matter if you use centimeters or inches. This makes it easier to compare climbers who may use the metric system compared to an American climber who uses inches and feet.
For example, Kai Lightner is 75 inches tall and has an arm span of 82 inches: 82/75=1.09. This is an exceptionally large ape index, especially compared to Adam Ondra who is very close to a neutral ratio: 73.6/73.2=1.01.
Method #2: Difference Between Wingspan & Height
For this second method, you simply subtract arm span minus height. A positive number means you have longer arms relative to your height, while a negative number means you have shorter arms. A zero would mean you’re neutral and that both your height and arm span measure the same.
If you use inches and this second method, you’ll find that a lot of professional climbers are closer to 1-4+, with the highest ape indexes getting closer to 6-7+. In centimeters, it’s not uncommon to see numbers closer to 10-18+ for the highest indexes.
Using the same climbers from above, Kai Lightner’s index is +7″ (82 minus 75) while Adam Ondra is only +0.4″ (73.6 mins 73.2).
Where Did Ape Index Come From?
Ape index is a phrase that started as climbing slang, but the origins of arm span compared to height actually date back to Roman times in 15 BC.
An architect and engineer, Vitruvius Pollio, made a claim that a “well made man” of good proportions had an arm span equal to his height. Many years later around 1487-1490, Leonardo da Vinci illustrated this concept in his now-famous drawing called the The Vitruvian Man.
Does Ape Index Make a Big Difference in Climber Ability?
Ape index doesn’t make a big difference in climber ability or skill, and you shouldn’t worry if you have a lower ape index or a higher one. That being said, it can be important to understand your body shape and size so you can use your physical features to your advantage and train your weaknesses.
Some people still believe that a higher ape index can positively affect rock climbing performance, but not everyone is one the same page. We were a little skeptical, so we dug deeper into what the science says.
What does science say about ape index and performance?
There have been multiple studies that have looked at physical attributes in comparison to rock climbing performance, and in the past the results have been quite mixed. Most recently in March 2023, a review of studies from 2000-2021 showed that ape index did not play a critical role in rock climbing ability or performance.
Here are a few examples of some studies that explored the topic:
In 2003, Watts et al.(1) found that the climbers in their study did have a larger ape index than the control group, but that it didn’t seem to affect their climbing ability compared to other climbers. The researchers did mention that this could be due to the ‘relatively small variability in ape index among the climbers.’ However, they did find that the climbers had a more narrow shoulder structure, which means more of their arm span comes from their actual arms than their torso. They suggested this could positively affect reach distance, which could be a more significant factor than ape index alone.
Mermier et al. (2000)(2) included ape index in their characteristics of climbers and concluded that a large portion of the various abilities in climbing were explained by trainable variables and not by specific anthropometric characteristics (like ape index), and that engaging in a training program is more important that natural characteristics.
On the other hand, Magiera et al. (2007)(3) found that ape index was one of the variables that had the highest diagnostic value along with technique and some other factors.
Most recently, in March of 2023 Ginszt et al.(4) published a brief review of characteristics of sport climbers in previous studies from years 2000-2021. In reference to ape index, they concluded that “ape index did not differ significantly between sport climbers of various skill levels” and further explained that their review also showed that “anthropometric variables such as ape index and height do not seem to be crucial in climbing activity.“
Does a High Ape Index Make You a Better Climber?
All this science points towards one fact: trainable factors are more predictive of climbing ability than any natural anthropometric measurements like arm span, height, or weight. This means years of climbing experience, weekly training hours, and flexibility will make you a better climber more than ape index ever will. So take our advice and focus on your training more than your body shape.
That being said, we think its important to know and understand your body shape so you can use your strengths to your advantage and work on your weaknesses. This will help you find your ideal style and show you where you thrive while climbing.
Ape Indexes of Famous Climbers
You can use this chart to compare your own ape index to some of the greatest climbers in the world. Take note how Adam Ondra’s ape index is quite small (1.01 or +0.4 inches) while Daniel Woods’ ape index is quite large (1.1 or +7). These two are arguably the greatest climbers of this generation, so it’s easy to see how ape index may not contribute to performance as much as one may think.
|Climber||Arm Span||Height||Ape Index Type 1 (Arm Span/Height)||Ape Index Type 2|
(Arm Span – Height)
|Kai Lightner||82 inches (208cm)||75 inches (190.5cm)||1.09||+7″ (17.5cm)|
|Matt Fultz||77 inches (195.6cm)||71 inches (180.cm)||1.08||+6″ (15.2cm)|
|Kai Harada||70.9 inches (180cm)||66.5 inches (169cm)||1.07||+4.3″ (11cm)|
|Ashima Shiraishi||61 Inches|
|Alex Johnson||68 inches|
|Ethan Pringle||74 inches (188cm)||70 inches (177.8cm)||1.06||+4″ (10.2cm)|
|Dave Graham||74 inches (188cm)||70 inches (177.8cm)||1.06||+4″ (10.2cm)|
|Daniel Woods||72 inches (182.9cm)||68 inches (172.7cm)||1.06||+4″ (10.2cm)|
|Tomoa Narasaki||70.9 inches (180cm)||66.9 inches (170cm)||1.06||+4″ (10cm)|
|Kyra Condie||68 inches (172.7cm)||64 inches (162.6cm)||1.06||+4″ (10cm)|
|Jan Hojer||78 inches (198cm)||74 inches (188cm)||1.05||+3.9″ (10cm)|
|Tomoa Narasaki||70.9 inches (180cm)||66.9 inches (170cm)||1.06||+3.9″ (10cm)|
|Shauna Coxsey||67.5 inches (171.5cm)||64.2 inches (163cm)||1.04||+3.3″ (8.5cm)|
|Alex Honnold||74 inches (188cm)||70.9 inches (180cm)||1.04||+3.1″ (8.5cm)|
|Paul Robinson||74 inches (188cm)||71 inches (180.3cm)||1.04||+3″ (7.6cm)|
|Carlo Traversi||67 inches|
|Chris Sharma||74.5 inches (189.2cm)||72 inches (182.9cm)||1.03||+2.5″ (6.3cm)|
|Jongwon Chon||72 inches (183cm)||69.7 inches (177cm)||1.03||+2.4″ (6cm)|
|Alex Puccio||65 inches (165.1cm)||63 inches (160cm)||1.03||+2″ (5.1cm)|
|Sasha DiGiulian||64 inches (162.6cm)||62 inches (157.5cm)||1.03||+2″ (5.1cm)|
|Emily Harrington||64 inches (162.6cm)||62 inches (157.5cm)||1.03||+2″ (5.1cm)|
|Stefano Ghisolfi||68.5 inches (174cm)||66.9 inches (170cm)||1.02||+1.6″ (4cm)|
|Jonathan Siegrist||67 inches (170.2cm)||65.5 inches (1664.cm)||1.02||+1.5″ (3.8cm)|
|Magnus Midtbo||69.3 inches (176cm)||68.1 inches (173cm)||1.02||+1.2″ (3cm)|
|Jimmy Webb||73 inches (185.4cm)||72 inches (182.9cm)||1.01||plus1″ (2.5cm)|
|Brooke Raboutou||63 inches (160cm)||62 inches (157.5cm)||1.01||plus1″ (2.5cm)|
|Nalle Hukataival||68.5 inches (174cm)||68 inches (172.7cm)||1.01||plus0.5″ (1.3cm)|
|Adam Ondra||73.6 inches (187cm)||73.2 inches (186cm)||1.01||plus0.4″ (1cm)|
|Lynn Hill||62 inches (157.5cm)||62 inches (157.5cm)||1||0|
|Alex Megos||68.1 inches (173cm)||68.1 inches (173cm)||1||0|
|Tommy Caldwell||70 inches (178cm)||70 inches (178cm)||1||0|
|“Well Made Man”||x||x||1||0|
Do Elite Climbers Have High Ape Indices?
While it’s easy to assume that professional climbers may have a larger ape index, you’ll find in the table above that most of them don’t. In the past, studies have shown that rock climbers do tend to have a larger index than non-climbers, but that it doesn’t affect their skills when compared to other climbers. That being said, some of the best climbers in the world have a small ape index ratio, so it’s not a major factor in performance. Adam Ondra has some great thoughts in his video on the ideal climber body.
Conclusion – Should You Care About Ape Index?
After diving into the science and looking at the indexes of professional climbers, I think we can agree that ape index isn’t a deciding factor in your climbing ability. Perhaps it does have a small role to play, but in our experience, your time is better spent focusing on trainable factors that will dramatically affect your skills rather than letting your natural features determine your ability.
What is a good ape index?
According to the original reference to ape index in 15 BC by Vitruvius, a “well made mad” has an arm span that’s equal to his height. While it’s easy to assume that most people have this neutral ratio, that’s not always the case, and an ideal ape index depends on your sport.
What is a good ape index for climbing?
A positive ape index may be commonly seen amongst climbers, but there’s no evidence that it makes them more skilled. So a good ape index for climbing is whatever you want it to be – it’s more important to focus on your training and use your body measurements to your advantage.
What does a +2 ape index mean?
A +2 ape index means that a person’s arm span is two inches longer than their height. This is calculated by subtracting wingspan minus height.
What is ape index used for?
Ape index can be an indicator of a natural advantage in some sports, but it’s really more intended to illustrate your body shape and type so you can use your natural measurements to your advantage.
Is a positive ape index good?
A positive ape index can be good in some sports, but in climbing it hasn’t been shown to provide any kind of advantage. If anything, it’s great information to to have so you can use your natural body shape to your advantage.
- Watts PB, Joubert LM, Lish AK, Mast JD, Wilkins B. Anthropometry of young competitive sport rock climbers. Br J Sports Med. 2003;37(5):420-4. doi: 10.1136/bjsm.37.5.420. PMID: 14514533; PMCID: PMC1751349.
- Mermier CM, Janot JM, Parker DL, Swan JG. Physiological and anthropometric determinants of sport climbing performance. Br J Sports Med. 2000 Oct;34(5):359-65; discussion 366. doi: 10.1136/bjsm.34.5.359. PMID: 11049146; PMCID: PMC1756253.
- Magiera, Artur; Ryguła, Igor (2007). “Biometric Model and Classification Functions in Sport Climbing“. Journal of Human Kinetics. 18: 96–97.
- Ginszt, Michał1; Saito, Mika2; Zięba, Estera1; Majcher, Piotr1; Kikuchi, Naoki2. Body Composition, Anthropometric Parameters, and Strength-Endurance Characteristics of Sport Climbers: A Systematic Review. Journal of Strength and Conditioning Research ():10.1519/JSC.0000000000004464, March 17, 2023. | DOI: 10.1519/JSC.0000000000004464
- Banner photo from Alex Puccio’s SCARPA athlete page.