FPE Calculator

FPE calculator helps you calculate how much power a moving object has based on its speed and weight. It helps airgun enthusiasts determine the muzzle energy of their shots and helps them choose the right ammunition for different targets and needs.

FPE Formula:

\(\text{FPE} = \frac{\text{V}^2 \cdot \text{W}}{450240}\)
 

Where,

• FPE – Represents Foot-Pounds of Energy, measured in foot-pounds (ft-lb)
• V – Represents the velocity of the projectile, measured in feet per second (ft/s)
• W – Represents the weight of the projectile, measured in (grains)
• 450437 – Represents the conversion factor between grains and foot pounds

FPE Example:

Let’s say, we have a scenario where a projectile (like a bullet) is moving at a velocity (V) of 100 feet per second (fps), and the projectile has a weight (W) of 200 grains.

Now, using the formula:

\(\text{FPE} = \frac{\text{V}^2 \cdot \text{W}}{450240}\)

How to calculate FPE?

• First, we square the velocity of the projectile: 100 * 100 = 10,000
• Then, we multiply the squared velocity by the weight: 10,000 * 200 = 2,000,000
• Finally, we divide the result by 450240: 2,000,000 / 450240 ≈ 4.44 (approximately)

Therefore, when the projectile moves at 100 fps with a weight of 200 grains, it would have around 4.44 Foot-Pounds of Energy (FPE).

Common Examples of FPE: