F.O.C. Calculator To determine the F.O.C of a hunting arrow, install all the components you will be using on the shaft (points/broadheads, vanes, inserts, nock, etc.) Learn more about F.O.C Here Enter Arrow Length (A)(Required)This is the overall length of the arrow measured from the throat of the nock to the end of the shaft. (not including the point)This field is hidden when viewing the formArrow length / 2Arrow length divided by 2Enter Balance Point Length (B)(Required)Find the balance point. This is where the arrow balances perfectly. Mark the point, and measure from the throat of the nock. This field is hidden when viewing the formBP-AL/2This field is hidden when viewing the formResult x100F.O.C. %Email My Results (optional) Consent I agree to the privacy policy.