Recoil Energy Calculator

What this calculator does

This tool estimates the free recoil energy and recoil velocity of a firearm using conservation of momentum, a standard approach used in ballistics references.

The formula

Recoil momentum is estimated from the bullet’s momentum plus an allowance for propellant gas momentum (using an assumed gas exit velocity around 4700 ft/s, a common approximation). Recoil velocity = total momentum / firearm weight, and recoil energy = (firearm weight × recoil velocity²) / (2 × g), using standard ft-lb units.

Results are estimates for general reference; actual recoil varies with load, gun design, and how the firearm is held.