⚖️ Arrow FOC Calculator
Work out your arrow's Front-of-Center balance from its length and balance point, with guidance for target and hunting setups. More weight up front means steadier, dart-like flight.
⚖️ Front-of-Center balance
In the typical target range (~7–15%). Steady flight with good downrange speed.
FOC = ((balance point − arrow length ÷ 2) ÷ arrow length) × 100. More weight up front raises FOC, trading a little speed and range for steadier flight and deeper penetration. Rough guidance: target archery runs about 7–15% (many target archers ~10–12%), bowhunting about 10–15%.
Balance is a tuning lever
Where an arrow balances changes how it flies. Shift weight forward and it stabilises quickly and drives through resistance; leave it tail-heavy and it wanders. FOC puts a single number on that balance so you can compare arrows and dial in your build.
There's a trade-off: high FOC is stable and hits hard but drops sooner at distance, while low FOC is flat and fast but less forgiving. Most archers land in the single-digit-to-mid-teens percent range — use this calculator to see where your current setup sits and tune point weight from there.
❓ Frequently Asked Questions
What is arrow FOC?
FOC (Front Of Center) is the percentage of an arrow's total length by which its balance point sits ahead of the exact centre. Weight concentrated toward the point raises FOC and makes the arrow fly more like a dart — nose-forward and stable.
How do I measure and calculate FOC?
Balance the finished arrow (point, insert, nock, and fletching all fitted) on an edge to find its balance point, then measure that distance from the throat of the nock. FOC% = ((balance point − arrow length ÷ 2) ÷ arrow length) × 100.
What FOC should I aim for?
As rough guidance, target and indoor archers usually run about 7–15% (many settle around 10–12%), while bowhunters often prefer about 10–15% for steadier flight and deeper penetration. There's no single correct number — it depends on your goals and setup.
What does higher FOC do?
More weight up front makes the arrow more stable and forgiving and can improve penetration, but it also drops faster at distance because the arrow sheds speed sooner. Lower FOC flies flatter and faster but is less forgiving of imperfect release.
How do I change my FOC?
The biggest lever is point and insert weight — heavier up front raises FOC. Longer shafts, lighter nocks, and smaller fletching also shift the balance forward. Change one thing at a time and re-measure.