What Is FOC in Archery and How to Calculate It?

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Archery is often a game of inches. As a result, archers often find themselves making tiny adjustments to their setup in the hopes of improving their shot or overall performance, even if only just. Optimizing your arrows is just one way to improve your shot, and there are multiple ways to do so.

In recent years, more and more archers have been exploring the importance of an arrow’s FOC, or front of center weight. The FOC of an arrow represents how much of the arrow weight is found in its front half. But why is FOC so important, and is there such a thing as good or bad FOC?

This guide to FOC discusses its effect on your shot, as well as how to calculate it. We also discuss the idea of a ‘good’ or desirable FOC, and when you might want to play with increasing your FOC.

What is FOC in Archery and how Important is It?

FOC in archery refers to an arrow’s front of center weight. The reason we discuss an arrow’s FOC is because arrows tend to have their weight concentrated in the front half, as a result of the arrowhead generally weighing more than the other parts of the arrow.

This also results in an arrow’s center of mass or balance point being biased towards the front of the arrow, rather than being located in, say, the dead center of the arrow shaft. So, your arrow’s FOC affects how it flies and its trajectory, to an extent.

The jury’s still out regarding the true importance of FOC. It’s true that there tends to be an FOC that most, if not all, professional archers in a given event or category work with. For example, most archers at indoor tournaments will shoot with a significantly higher FOC than you’d expect archers at outdoor tournaments to use. Bowhunters in particular tend to prefer a higher FOC, as this can help the arrow sink into its target better if it connects poorly (i.e. hitting a bone on impact).

However, you’ll find that most professional archers and experts on the topics recommend that you don’t fixate on your arrow’s FOC all that much. While it does have some impact on your performance, it’s not the be all and end all of your shot, unless you’re shooting with an FOC that is absolutely extreme. 

How do you Calculate FOC on Arrows?

Easton Archery has published a formula for calculating FOC on arrows. It can seem a little involved, but once you’ve gone through the process a few times it basically becomes second nature.

To start off with, you’ll need to divide the length of the arrow in two. Then, find the balance point. The balance point is the point at which you can balance the arrow without issue (usually towards the front of the shaft). Then, subtract the distance from one end to the center from the balance point. Multiply this number by 100, and then divide it by the total length of your arrow.

How to calculate arrow FOC or Front of Center weight percentage
How to calculate arrow FOC or Front of Center weight percentage

If that all seemed a bit complicated, you can also use Easton Archery’s FOC calculator on their webpage: https://eastonarchery.com/foc-calculator/

What is a Good FOC for Arrows? 

The ideal FOC for an arrow will vary depending on a range of factors. The environment that the arrow is being shot in is an important part of the equation, as is the style of archery that is being practiced.

For example, if you’re shooting field points, you’ll likely want an FOC somewhere between 8-11%, compared to between 12-15% if you’re shooting broadheads on a hunting arrow. If you shoot with fingers or with shorter-than-usual arrows, you’ll likely want a FOC of around 15% or so.

Having said that, it’s important to note that there’s a balance that needs to be maintained when it comes to FOC. Generally speaking, an FOC higher than 18% is unlikely to be of much benefit and will likely make your arrows too point-heavy, as well as negatively impacting how they fly.

FOC may seem complex at first blush, but it’s important not to overthink or place too much emphasis on it. While FOC affects how your arrow flies, it’s most likely not going to make or break your shot. Tweak it to optimize your arrow setup, and if you’re unsure, try to keep it below 18%.

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