Bullet energy and recoil calculator
Muzzle energy, energy downrange and free recoil, from your own numbers.
Enter your bullet weight and muzzle velocity to get muzzle energy in foot-pounds. Add the bullet’s ballistic coefficient to see the energy left at every 100 yards out to 1,000, and your gun’s weight to see its free recoil. Nothing is filled in for you and nothing leaves your device; your entries are remembered here for next time.
Energy
Enter your bullet weight and muzzle velocity.
Free recoil
Add your gun weight (and bullet) to see recoil.
How it is worked out
Energy. Kinetic energy is half the mass times the velocity squared. In the units shooters use, that is bullet weight in grains times velocity in feet per second squared, divided by 450,436. Many published tables divide by 450,240 instead, which is the same formula with a slightly rounder figure for gravity; the two differ by less than a twentieth of one percent.
Energy downrange. The remaining velocity at each distance comes from the same point-mass solver as the ballistic calculator, in standard conditions (59°F, sea level). Rows at or below Mach 1.2 are marked, because that is where a real bullet’s drag stops following the reference table. What the BC on the box does and does not tell you is in Ballistic Coefficient & BC Selection.
Free recoil. The gun takes up the momentum of everything that leaves the muzzle: the bullet, and the powder gas, which is taken to leave at about 4,000 fps (most published rifle tables use 4,000; some use up to 4,700, and a higher figure gives more recoil). The gun’s rearward speed is that momentum divided by its weight, and free recoil energy is half its mass times that speed squared. “Free” means unrestrained: what you feel also depends on stock fit, a brake or suppressor and the action, none of which a formula can see.
What energy does not tell you. Foot-pounds describe what a bullet carries, not what it does when it arrives. How it behaves in a target depends on its construction and its speed at impact as much as its energy. That is the subject of Terminal Ballistics.