Arrow Front of Center (FOC) Calculator

Front of Center (FOC) is critical to understand as it directly impacts the arrow trajectory and flight. FOC becomes especially important as the flight distance increases, so long range archers listen up!

We have created a FOC calculator that will help you figure out your arrow’s FOC based on the Arrow Length and the Balance Point. Input those two items in the calculator below to get started.

How to Measure FOC

  1. Measure the Arrow Length (in inches): Starting from the nock’s throat, measure to the end of the arrow shaft. Do not measure the tip due to differing sizes depending on the type of tip used such as broadheads.
  2. Balance the Arrow: Using a sharp item as the balance point (can also use a pencil, your finger, etc) and find the balance point. Your arrow should have everything on it as you would if you were normally shooting it.
  3. Measure the Balance Point (in inches): Measure from the nock’s throat to the balance point you determined in step 2.

Calculations based on the AMO method

What Should your FOC Range Be?

In general, you should shoot for the 10-15% range.

However this could differ depending on the type of arrow you use as well as your overall goals. Target shooting should be on the lower end of the range (7-11%) while hunting will be on the high end of the range (12-15%).

A general rule of thumb is to err on the side of having a higher percentage as it will carry more power and penetration. You should also consider your bow’s kinetic energy. But don’t go too far past the 15% range as your arrow will become less aerodynamic.