Bullet Energy Calculator

Find a bullet's kinetic energy from its mass and speed.

Bullet mass

Speed

Kinetic energy (J) 640

Energy (ft·lb) 472.04

Formula: KE = ½·m·v²

Step-by-step with your numbers:

1. Values used:

2. Bullet mass = 8

3. Speed = 400

5. Kinetic energy = 640J

6. Energy = 472.04ft·lb

Did we solve your problem today?

A bullet's kinetic energy measures its capacity to do damage on impact.

The math behind it

KE = ½·m·v². Speed matters most because it is squared. 1 J ≈ 0.738 ft·lb.

8 g at 400 m/s → 640 J (about 472 ft·lb).

Energy or momentum for stopping power?

Both matter; energy reflects damage potential, momentum reflects push.