Extreme Outfitters - Archery Tools
Use this FOC calculator to determine your arrow’s Front of Center (FOC) and understand how your setup impacts accuracy, stability, and penetration. Whether you’re building arrows for hunting or dialing in a target setup, knowing your FOC helps you make smarter gear decisions.
Units
Measurements
Your result
FOC percentage
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How it works
FOC% = ((balance point − arrow length ÷ 2) ÷ arrow length) × 100Measure arrow length from the bottom of the nock groove to the tip of the shaft (not the point). Find the balance point by resting the arrow on your finger — measure from the nock end to where it balances.
Designed for serious arrow builders, this upgraded system delivers smoother cuts, automatic squaring, and repeatable accuracy—so you can trust every arrow you shoot.
FOC, or Front of Center, is the percentage of an arrow’s total length where its balance point sits forward of center. In simple terms, it tells you how much of your arrow’s weight is concentrated toward the front.
A higher FOC means more weight is positioned toward the tip, while a lower FOC means the weight is more evenly distributed.
FOC directly affects how your arrow behaves in flight and on impact.
FOC is calculated using arrow length and the balance point of the arrow:
FOC (%) = ((Balance Point – (Arrow Length ÷ 2)) ÷ Arrow Length) × 100
This calculator removes the guesswork and gives you an accurate result instantly.
Typical FOC ranges:
These ranges provide a balance between stability, speed, and penetration. The ideal setup depends on your bow, arrow build, and intended use.
Adding weight to the front increases FOC.
Longer arrows can shift balance and reduce FOC.
Different arrow shafts distribute weight differently.
Weight added to the rear lowers FOC.
Understanding your FOC is just the start.
The right combination of:
determines how your arrow performs in real-world conditions.
Dial in your setup with purpose, and shoot with confidence.
