What is Arrow Front of Center (F.O.C)?
"F.O.C. stands for “front-of-center.” FOC describes the percentage of the arrow’s total weight that is located in the front half of the arrow." (Easton Archery)
Why is it important?
A higher FOC percentage means that more weight is concentrated towards the front of the arrow, while a lower FOC percentage means that more weight is towards the rear.
High FOC (+15%)
Typically, arrows with higher FOC percentages have more stability during flight and better accuracy, as they tend to resist the effects of wind and other external factors.
They also tend to penetrate better upon impact, making them popular for hunting big game. But they tend to drop faster due to the heavier front end.
Low FOC:
If your FOC is too low, your arrow flight can be farther but wobbly as most of arrow weight is staying at the rear. The result: you miss the target.
So what's ideal FOC recommendation?
- Hunting: Easton Archery recommends a range of 10 - 15% FOC by adding or removing the weight at front/rear of arrows.
- Indoor archery: 7 - 15%
- Outdoor: 10 - 15%
How to Calculate Arrow F.O.C?
Here is the formula:
FOC = [Balanced Length - (Arrow Length/2)] * 100 / Arrow Length
How to Find the Balanced Point of Arrow?
Follow these steps:
- Find an shaft edge where you arrow can balance without resistance
- Try to balance it
- Mark the point with this chalk or marker
- Measure the length from the throat of the nock to the balancing point.
