Arrow FOC Calculator
Arrow FOC Calculator and Build Calculator
Use this arrow FOC calculator to calculate front of center percentage, finished arrow weight, estimated arrow speed, kinetic energy, momentum, and balance point before you build. Choose a Black Eagle shaft or enter a custom arrow setup to compare components and dial in the right hunting, target, or high-penetration arrow build.
Calculate Front of Center, Arrow Weight, Speed, KE, and Momentum
This calculator helps bowhunters and archers understand how shaft length, spine, GPI, insert weight, broadhead weight, nock weight, vanes, wraps, draw weight, draw length, and bow speed change FOC and overall arrow performance.
Your Arrow Build
Excellent MatchHunting Build
Arrow Balance Visual (example arrow not to scale)
Center 20.2"
Balance 28.5"
Excellent for most hunting setups. Provides strong broadhead stability while maintaining a forgiving trajectory.
Well suited for larger game where penetration is a priority.
Strong energy for whitetail, hogs, black bear, and many elk setups with the right broadhead and shot placement.
Balanced hunting weight with a good mix of speed, penetration, and quieter bow performance.
Rampage 300
Rampage is a hard-hitting hunting shaft with excellent total weight and broadhead control for larger game.
Other great choices
Why FOC Matters
High FOCYour FOC Result
This build is in the all-around hunting range.
Speed / Target
Lower to moderate FOC keeps finished weight down and helps preserve arrow speed. This is useful when a flatter trajectory matters most, such as target setups, 3D, or lighter hunting builds.
All-Around Hunting
Moderate to high FOC is the sweet spot for most hunting arrows. It improves broadhead control and arrow recovery without giving up too much speed.
Penetration / Big Game
Higher FOC moves more weight toward the front of the arrow. That helps fixed blades steer cleaner, improves impact stability, and supports deeper penetration on bigger animals.
Arrow FOC FAQ
1. What is FOC (Front of Center)?
FOC is the percentage of an arrow's weight located in front of its center point. It influences arrow stability, broadhead flight, and overall performance.
2. What is a good FOC for hunting arrows?
Most hunting arrows perform well with an FOC between 10% and 15%. Some archers prefer higher FOC for larger game or specialized setups.
3. Does a higher FOC increase penetration?
Higher FOC can improve arrow stability and broadhead alignment, but penetration also depends on total arrow weight, momentum, broadhead design, and shot placement.
4. What's the difference between momentum and kinetic energy?
Kinetic energy measures impact energy, while momentum reflects an arrow's ability to continue moving through resistance. Both are useful when evaluating hunting performance.
5. Does a heavier arrow always penetrate better?
Not always. Heavier arrows generally carry more momentum, but the best setup balances arrow weight, speed, bow performance, and the game being hunted.
6. How does arrow length affect FOC?
Increasing arrow length shifts the balance point and can change FOC. Longer arrows may require additional front weight to maintain the same percentage.
7. Can I use this calculator with any arrow brand?
Yes. This calculator works with virtually any arrow brand by entering your shaft and component specifications.
8. Why is total arrow weight important?
Total arrow weight affects speed, trajectory, noise, momentum, and kinetic energy. Finding the right balance helps optimize overall performance.
9. Does changing broadhead weight change FOC?
Yes. Increasing broadhead or insert weight moves the balance point forward and typically increases FOC.
10. Why should I calculate FOC before building arrows?
Calculating FOC before assembling arrows helps you choose components that achieve your desired balance, weight, and performance without unnecessary trial and error.
Calculations are estimates for build planning and comparison. Confirm final spine, finished weight, and component setup before hunting or tournament use.