Ape Index (Arm to Height Ratio): Measure to Find Out if Yours is Ideal

Written by Joshua Leaf | Updated on September 30, 2021

Measuring your wingspan, or arm-to-height ratio (otherwise known as ape index) can be insightful for athletic purposes like climbing and fighting. In addition, some people measure these ratios to see if their proportions are within a normal range, or to gauge aesthetics.

Jump down below to see how they’re measured and if it’s beneficial to have long arms, legs or wingspans.

Should Your Arm Length or Wingspan Be Equal to Your Height?

Humanity inspires art, and one mathematically accurate art piece often referenced when it comes to wingspan and height is Leonardo da Vinci’s “Vitruvian Man”. Inspired by Vitruvius’ writing, this drawing shows da Vinci’s perception of the perfect male body.

The Vitruvian Man has a wingspan equal to his height. The circle inscribed around him indicates his wingspan, and its radius is the same length as the side of the square, which represents his height.

It’s believed that ideally, the wingspan-to-height ratio should be 1:1.[1] However, this isn’t one-size-fits-all and what looks most attractive depends on a person’s body size. If wingspan and height differ by 2-3 cm, it’s usually unnoticeable, and a person isn’t considered disproportionate even up to a difference of 10 cm.

This goes to show that there’s a wide range of what’s aesthetically pleasing in the eyes of the general population.

How is Wingspan and Arm-to-Height Ratio (Ape Index) Measured?

Wingspan, arm-to-height ratio, and ape index can all be measured easily at home. All that’s needed is a measuring tape, a thread, and a calculator – or one can always use one of the many online tools available instead!

Arm Span or Wingspan

You can find your wingspan by simply determining the distance between the ends of both ends. It’s measured fingertip-to-fingertip. To estimate your wingspan:

  • Take a long thread or piece of yarn and stand with your chest against a wall
  • While standing, gather the thread in both hands
  • Keep holding the string and stretch out your arms so they’re parallel to the ground
  • Have a friend or family member measure the length of the extended thread

To find the ape index, arm-to-height, or wingspan-to-height ratio, one needs to divide this measurement by the person’s total height.

Ape Index

The wingspan-to-height ratio and the difference between wingspan and height are two ways to express the ape index.[2]

Ratio

The wingspan is divided by the total height, giving the ape index. For example, if both wingspan and height are 180 cm, the ape index will be 180/180, which is 1.

On the other hand, if the wingspan is 175 while the height is 170, the ape index will be 1.03. Hence, if the wingspan is longer than height, the ape index will be greater than 1. Meanwhile, if it’s less than height, the ape index will be less than 1.

Difference

The second way to calculate the ape index is to subtract height from the wingspan. In the case of both wingspan and height being 180 cm, the ape index will be 0.

If, like in the ratio example, the wingspan is 175 and height is 170, the ape index will be 5 (175 – 170 = 5). As a result, a wingspan greater than height will give a positive ape index, and a wingspan shorter than height will provide a negative ape index.

Other Ratios to Consider

There’s a few other ratios people can consider to check if their bodies are proportionate, including:

  • Hobbit Index – Ratio of the hand and foot lengths – smaller hands mean smaller feet.
  • Snake Index – Represents how wide you’re able to open your mouth.
  • Sloth Index – Difference between the leg length (hip to heel) and arm length (deltoid to fingertip).

Benefits of Being Proportionate

People like models and bodybuilders focus on building the perfect human body, and body measurements and proportions form a significant part of this. People generally see a proportionate body as an attractive body. Whether it’s the wingspan-to-arm ratio, leg-to-body ratio, or shoulder-to-waist ratio, balanced human ratios generally enhance aesthetics.

Why Does Attractiveness Matter?

Conventionally attractive people undoubtedly benefit from the “halo effect” – humans perceiving beautiful people as more capable and intelligent solely due to their appearance. Much of this bias is subconscious, but it has tangible consequences.

More Wealth

Attractive people earn more – employers are willing to offer a 10.5% higher salary to conventionally attractive people instead of those seen as unattractive just by viewing their photographs.[3] Attractive real estate brokers also bring home more dough than their unattractive counterparts.[3]

More Confidence

Since most consider attractive people more friendly and self-confident by default, this belief creates a perfect circle as they receive more validation and encouragement than unattractive peers. As such, they turn out to be more confident as adults.

Even as children, teachers expect cuter children to perform better, giving them preferential treatment and improving their social and communication skills.[3]

More Options

Many children dream of being rich and famous. However, unless they’re extremely smart, physically gifted, or entrepreneurial, being attractive is a prerequisite for money and fame. Conventionally beautiful people dominate careers like acting, modeling, and others that lead to stardom.

This fact seems even more valid in today’s world, as attractiveness increases a person’s chances to create a social media career. Most fitness influencers, Instagram models, TikTok stars, and even Facebook influencers are overwhelmingly attractive, and social media is one of the most lucrative career options right now.

Benefits of Long Arms

Long arms present apparent benefits when it comes to sports. Sports like rowing, bouldering, and rock-climbing benefit from the more extensive reach and range of motion that longer arms provide. Long-armed people may be able to reach higher and generate more centrifugal force to row harder.

Most sports that involve catching and throwing a ball, like baseball, cricket, or soccer, will be more accessible since people with long arms have a more extended reach, making it easier for them to catch. They can also throw a ball faster and farther since they can generate more centrifugal force.[4]

Long-armed people also have a distinct advantage in combat-based sports like boxing and kickboxing since they can land punches from afar. A tall wrestler with long arms can secure grips more quickly than those with shorter arms in wrestling.

Besides sports, long arms can sometimes indicate good health. Long-armed people are also less likely to develop Alzheimer’s when they get older. An increase of 1 inch in wingspan lowers the chance of Alzheimer’s by 10% and of dementia by 7%.[5]

Arm Lengthening Surgery

Once a person grows into adulthood, their skeleton matures, and the only way they can change their limb proportions is through surgery. Arm lengthening surgery is not as standard, and in rare cases, patients with arm length discrepancies or deformities get their arms lengthened.

However, just like some people want to get taller and get leg lengthening surgery, some get cosmetic arm lengthening surgery. These patients usually have a much shorter wingspan than their height or uneven arms and want to achieve a more proportional body.

On the other hand, the ratio between the upper and lower portions of the limbs, also known as the intra-limb ratio, plays a small role in overall attractiveness. Some may believe that their arms are too disproportionate and want to change the ratio of their arms themselves.

How Does Arm Lengthening Work?

Generally, the upper bone or humerus is the bone that’s lengthened. The surgeon cuts bone and attaches an external fixator to the humerus via rods, and the patient gradually increases the bone length manually. Once humerus lengthening is complete, the bone is allowed to heal fully, after which the surgeon removes the external fixator.

This method can lengthen the humerus up to 9 cm.[6] If you consider such a procedure to make your body look more proportionate or to optimize your ape index, make sure to research and find a reliable doctor and follow their advice to maximize your chances of achieving optimal results.

References

[1] Science Buddies & De Brabandere, S. (2017, March 16). Human Body Ratios. Scientific American. https://www.scientificamerican.com/article/human-body-ratios/

[2] Beale, A. (n.d.). Ape Index Calculator: What’s Your Ape Index? 99Boulders. https://www.99boulders.com/ape-index-calculator

[3] Baer, D. (2014, November 10). Scientists Identify 3 Reasons Why Attractive People Make More Money. Business Insider. https://www.businessinsider.in/strategy/scientists-identify-3-reasons-why-attractive-people-make-more-money/articleshow/45102751.cms

[4] McAllister, C. J. (2020, March 31). The Advantages of Long Arms in Sports. How They Play. https://howtheyplay.com/misc/The-Advantages-of-Long-Arms-in-Sports

[5] Fletcher, D. (2011, April 21). What does your body say about you? Mirror. https://www.mirror.co.uk/news/uk-news/what-does-your-body-say-about-you-123891

[6] Agrawal, H. K., Singh, B., Garg, M., Khatkar, V., Batra, S., & Sharma, V. K. (2015, June). Cosmetic arm lengthening with monorail fixator. Chinese Journal of Traumatology, 18(3), 170-174. https://www.sciencedirect.com/science/article/pii/S1008127515000826

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