Use this calculator to find the muzzle energy of any less-lethal launcher and projectile combination. Enter the velocity in feet per second (FPS) and the projectile weight in grams — the calculator returns energy in joules along with context about what that number means in practice.
Quick presets are included for common less-lethal rounds so you can compare values instantly. Keep in mind that joules alone don’t tell the whole story — the disclaimer below the result explains what else matters.
Less Lethal Energy Calculator
Calculate muzzle energy in joules from velocity and projectile weight.
feet per second (FPS)
grams (g)
Please enter valid values for both velocity and projectile weight.
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joules
joules
⚠ Energy is only part of the picture
Joules measure kinetic energy at the muzzle — but real-world effect depends on projectile type (hard vs. soft, shape, fragmentation), distance to target, shot placement, and the target’s clothing, build, and pain tolerance. A low-joule soft round can incapacitate effectively; a high-joule hard projectile at close range can cause serious injury. Always follow manufacturer guidelines and applicable law.
Joules measure kinetic energy at the muzzle — but real-world effect depends on projectile type (hard vs. soft, shape, fragmentation), distance to target, shot placement, and the target’s clothing, build, and pain tolerance. A low-joule soft round can incapacitate effectively; a high-joule hard projectile at close range can cause serious injury. Always follow manufacturer guidelines and applicable law.