Bullet Kinetic Energy Calculator
Calculate bullet kinetic energy in ft-lbs and Joules from velocity and bullet weight.
Used in sport shooting, ballistic analysis, and physics study.
Bullet kinetic energy determines terminal performance — how effectively a bullet transfers energy to the target. It is one of the most important factors in ethical hunting.
Kinetic energy formula: KE = 0.5 × m × v²
In hunting units: KE (ft-lbs) = (bullet weight in grains × velocity in fps²) / 450,437
Or in metric: KE (Joules) = 0.5 × mass (kg) × velocity (m/s)²
Minimum recommended energies for ethical hunting (ft-lbs):
- Small game (rabbit, squirrel): 100–300 ft-lbs
- Medium game (deer, antelope): 1,000–1,500 ft-lbs
- Large game (elk, moose): 1,500–2,500 ft-lbs
- Dangerous game (bear, buffalo): 3,000+ ft-lbs
Common calibers and typical muzzle energy:
| Caliber | Typical Muzzle Energy |
|---|---|
| .22 LR | 100–140 ft-lbs |
| .223 Rem / 5.56 NATO | 1,200–1,400 ft-lbs |
| .308 Win / 7.62 NATO | 2,400–2,800 ft-lbs |
| .30-06 Springfield | 2,700–3,100 ft-lbs |
| .300 Win Mag | 3,400–3,800 ft-lbs |
| .338 Lapua | 4,500–5,000 ft-lbs |
| .375 H&H (dangerous game) | 4,300–4,800 ft-lbs |
Energy at distance: Bullet energy decreases with range due to velocity loss. A .308 Win starts at ~2,600 ft-lbs at the muzzle and retains ~1,900 ft-lbs at 300 m — still suitable for deer.
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