Enter the weight (grains) and the velocity (fps) into the calculator to determine the FPE. This calculator can also determine the weight or velocity if the other variables are known.

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## FPE Formula

The following formula is used to calculate the foot-pounds energy (FPE) of a projectile.

FPE = V^2 * W / 450240

- Where FPE is the foot-pounds of energy
- V is the velocity of the projectile (ft/s)
- W is the weight of the projectile (grains)

To calculate FPE, square the project velocity, multiply the result by the weight in grains, then divide by 450240.

## FPE Definition

FPE is short for foot-pounds of energy. This term is used to describe the kinetic energy contained in a projectile.

## Example Problem

How to calculate FPE?

**First, determine the velocity of the projectile.**For this example, the projectile is moving at 700 ft/s.

**Next, determine the weight of the projectile.**The projectile, a pellet, in this case, weighs 12.5 grains.

**Finally, calculate the FPE.**Using the formula above, the foot-pounds of energy is calculated as:

FPE = V^2 * W / 450240

FPE = 700*700&12.5/450240

FPE = 13.603