Arrow FOC Calculator: Front of Center Percentage

Your details

Choose the unit you measured in. Both give the same FOC percentage.
Measure from the nock throat (bottom of the nock groove) to the end of the shaft, not including the point or broadhead.
in
Balance the fully built arrow (with nock, vanes, insert, and point attached) on a finger or dowel and measure from the nock throat to that balance point.
in
Choose your primary use. This adjusts the ideal-range guidance shown in the results.
FOCHunting range (11-18%)
12.5%

Front-of-center percentage

Arrow midpoint14
Balance point offset from midpoint3.5
Ideal FOC min11%
Ideal FOC max18%
12.5 %
Too low<7Target7-11Hunting11-18High FOC18-30Extreme30+

FOC is 12.5% - in the ideal range for hunting with broadheads.

  • The recommended FOC for hunting with broadheads is 11-18%. Your arrow is at 12.5%, which is inside that range.
  • Your arrow is well balanced. For fine-tuning, a heavier broadhead raises FOC and penetration; a lighter field tip lowers it and flattens trajectory.
  • The balance point sits 3.50 in ahead of the midpoint (14.00 in from the nock throat).
  • FOC does not account for total arrow weight or speed. Pair this result with a kinetic energy calculation to assess penetration potential fully.

Next stepFine-tune your build and re-measure if you change any component. Even swapping vanes can shift FOC by 1-2%.

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