Articles ยป Ape Index Climbing

Ape Index Climbing

Have some of your climbing friends been talking about their ape index? The jargon in climbing seems to be endless, and now suddenly we’re talking about apes?

What is Ape Index?

Ape Index is a term that describes your arm span (wingspan) in relation to your height. The ape index can be expressed as either a ratio or a number (negative, positive, or zero).

A zero, or a neutral ape index, means that your wingspan is the same length as your height. So if my wingspan was 72 inches and my height is 72 inches (6 feet), then my ape index would be zero.

A positive ape index would look like this. My wingspan is 73 inches and my height is still 72 inches, I would have a positive ape index of 1!

What would the values be for a negative ape index?

Well, if you’re wingspan is 71 inches and you’re height is 72 inches. Your ape index will be -1.

How do I calculate my own ape index?

The algorithm to calculate the ape index does not require a mathematics PHD. In fact, I guarantee that by the end of this article you will understand how to calculate the ape index and ape index ratios for you and all your climbing partners.


Measure once, cut twice. We need to take two measurements to calculate the ape index.

This will be easier with a second person, so grab your climbing partner!

First, we need to measure our arm span. Bust out the tape measurer and bring your arms out parallel to the ground. Bring the tape straight across from middle finger to middle finger. The value you see is the length of your arm span!

Good job! We’re halfway done.

Now we need to measure your height. Stand up straight and measure!

Write down both your height and arm span so you don’t forget! Next, it’s time for the algorithm to calculate your own ape index.


Ape Index Ratio

If you’re curious about what your ape index ratio is then we can use divison to figure this out.

The formula is: Wingspan / Height = ape index ratio

Ape Index

If you want you’re straight up index, then all we need to do is use some subtraction:

The formula is: Wingspan – Height = ape index

Climbing out of the Endless Wall at the New River Gorge. Your ape Index doesn't matter on a ladder!

Do I want a Positive Ape Index or a Negative Ape Index?

Is a positive ape index good for climbing? Or do I want a neutral ape index, so everything can be perfectly balanced?

Your ape index is important to know, but will not define your climbing performance.

When I first heard about the ape index, also known as the ape factor, I immediately assumed that having a higher ape index ratio was going to be better. And I think that beginner climbers are going to have a higher advantage with a bigger ratio. You’ll be able to reach past cruxes and have an easier time getting to the next hold. Any climb with a reachy crux is going to feel a tad bit easier with a longer ape index.

But is this good in the long run?

I don’t think it is. I think that you’ll begin to use your larger ape index as a crutch. There are tons of techniques we can train within our climbing, but we can’t train our weaknesses if we don’t know what our weaknesses are.

If you have a positive ape index, don’t take it for granted. And if you use it, be conscious that you’re using it. But also keep an eye out for alternative beta that you can use that will improve your rock climbing ability in the long run.

If you have a negative ape index, be thankful for the extra technical training you get to endure! In the long run, you’ll see a huge improvement in your climbing performance.

In fact, there was even a study conducted in January, 2014 that aimed to find what factors were contributing to a climber’s success. The study looked at the ape index from elite climbers, but did not think that it mattered that much in the end. Instead, they found that trainable factors were a better indicator of a climber’s performance.

Frequently Asked Questions

What is a good ape index for climbing?

In climbing, it’s commonly believed that a positive ape index is good. And I would agree with that. Having a longer wingspan means that you’ll have more reach and be able to grab holds that might usually be hard to reach for other climbers. Famous climbers like Adam Ondra and Alex Megos have surprising ape indicies. Adam Ondra’s ape index is +0.4 inches. Alex Megos has a neutral ape index.

I believe that a positive ape index will help you initially, but technique and training can take you farther in the long run. But I have found that having a higher ape index has helped me overcome some tricky bouldering problems, while sacrificing development in my technique.

What does a +2 ape index mean?

A +2 ape index means that your wingspan is two inches longer than your height. In short, you have longer arms than your height. You can calculate your ape index using the subtraction method. Measure your height and measure your wingspan. Then subtract your body height from your arm span and that will give you your ape index. Most humans have an ape index around 0.

How do I find my ape index?

To find your ape index, measure your height and arm span. Then subtract your height from your arm span. The resulting value will be positive, negative, or zero, also known as neutral. This value won’t define your climbing. But it is helpful to know this for certain routes that may be reachy.

Photo of author
Rob developed ORB to help himself categorize and find all the outdoor gear he needed at great prices. He loves writing about the outdoors and climbing. Rob is a certified Single Pitch Instructor through the AMGA.

Leave a Comment