Try this out.

Enter both the Total AMO SShaft length and the Noc to Balance Point values and hit the Calculate button.

Try different values and see what effects they have on FOC.

FOC Calculator

Enter AMO Total Length AND Nock to Balance Point
then press the "Calculate" button:

Arrow Length

Nock to Balance Point

( % FOC )


Kinetic Energy / Momentum Calculator

Enter Arrow Weight AND Arrow Velocity then press the "Calculate" button:

Arrow Weight (grains)

Arrow Velocity

Kinetic Energy

(Slugs or lb.ft.-sec)