This app calculates the muzzle energy, momentum, power factor, and Taylor KO factor for a projectile based on the mass, velocity, and diameter. Muzzle energy is computed using the firearm industry's standard formula. Momentum is calculated using the standard formula. Power factor is mass in grains multiplied by velocity in feet per second, divided by 1000. This is used in IDPA and USPSA competitions. Taylor KO factor is a comparative measure of the knock-down power of a projectile. The formula was developed by John Taylor, an African game hunter, to compare the effectiveness of hunting cartridges.

The calculations in this app can be useful for hunting, reloading, target shooting, archery, and other activities involving projectiles.