Archery Calculators — Arrow FOC, Spine & Ballistics | ArcheryMetric

The ultimate archery toolkit. Calculate arrow FOC, kinetic energy, momentum, and spine. Professional ballistics tools for hunters and competitive target archers.

Popular Arrow Setups

Pre-calculated ballistics for common arrow length and bow speed combinations

FAQ

What is a good FOC for hunting arrows?

For hunting, an FOC between 12% and 15% is considered ideal. High FOC (above 15%) improves arrow flight stability and increases penetration power on impact.

How do I calculate kinetic energy for my bow?

Kinetic energy (KE) is calculated using the formula: KE = (Weight in grains × Velocity² / 450,240). Our tool automates this to help you meet minimum hunting requirements.

Does arrow length affect the required spine?

Yes. A longer arrow is more flexible (effectively weaker). If you increase arrow length, you usually need a stiffer shaft (lower spine number) to maintain proper flight.