Bullet Energy Calculator
Calculate kinetic energy of bullets for ballistics analysis and firearm performance
Calculate Bullet Kinetic Energy
Weight of the projectile (commonly measured in grains)
Speed of bullet (muzzle velocity or at target)
Bullet Energy Results
Formula used: E = ½mv² (Kinetic Energy)
Input values: m = 9.72 g, v = 853.44 m/s
Energy in Joules: 3539.769 J
Ballistics Analysis
Velocity: Supersonic
Mach number: 2.49
Energy class: High-Power Rifle
Power factor: 420.0
Energy Classification
Example Calculations
9mm Luger (124 gr @ 1150 ft/s)
Mass: 124 grains = 8.035 grams
Velocity: 1150 ft/s = 350.5 m/s
Energy: E = ½ × 0.008035 × 350.5² = 492.7 J = 363.3 ft-lbf
Application: Personal defense, law enforcement
.308 Winchester (150 gr @ 2820 ft/s)
Mass: 150 grains = 9.72 grams
Velocity: 2820 ft/s = 859.5 m/s
Energy: E = ½ × 0.00972 × 859.5² = 3594.7 J = 2648.9 ft-lbf
Application: Hunting, long-range shooting
.338 Lapua Magnum (250 gr @ 3000 ft/s)
Mass: 250 grains = 16.2 grams
Velocity: 3000 ft/s = 914.4 m/s
Energy: E = ½ × 0.0162 × 914.4² = 6779.8 J = 4995.2 ft-lbf
Application: Long-range precision, military
Energy Applications
Terminal Ballistics
Energy transfer to target on impact
Recoil Analysis
Firearm recoil prediction and management
Ammunition Selection
Comparing cartridge performance
Hunting Ethics
Ensuring adequate energy for clean kills
Physics Concepts
Kinetic Energy: Energy of motion (½mv²)
Velocity Squared: Energy increases with velocity²
Mass Effect: Linear relationship with mass
Momentum: p = mv (penetration factor)
Supersonic: Velocity > 343 m/s (1125 ft/s)
Understanding Bullet Energy
What is Bullet Energy?
Bullet energy refers to the kinetic energy of a projectile. Since bullets are kinetic projectiles (not explosive), their destructive power comes entirely from their kinetic energy. This energy is transferred to the target upon impact, determining the bullet's terminal ballistics.
Why is Velocity Critical?
- •Energy increases with the square of velocity
- •Doubling velocity quadruples energy
- •Small, fast bullets can carry tremendous energy
- •Velocity matters more than mass for energy
Physics Formula
E = ½mv²
Kinetic Energy Formula
- E: Kinetic energy (Joules or ft-lbf)
- m: Mass of bullet (kg or grains)
- v: Velocity of bullet (m/s or ft/s)
Practical Formula (US units):
E = (m × v²) ÷ 450,436.686 ft-lbf
where m is in grains and v is in ft/s
Muzzle vs Terminal Energy
Muzzle energy is calculated using muzzle velocity (at barrel exit).Terminal energy uses velocity at target impact, accounting for air resistance and distance.
Common Caliber Energy Ranges
| Caliber | Bullet Weight (gr) | Muzzle Velocity (ft/s) | Muzzle Energy (ft-lbf) | Application |
|---|---|---|---|---|
| .22 LR | 40 | 1,080 | 104 | Small game, plinking |
| 9mm Luger | 115-147 | 1,000-1,200 | 300-400 | Self-defense |
| .45 ACP | 200-230 | 800-900 | 350-450 | Self-defense |
| .223 Remington | 55-77 | 3,000-3,300 | 1,200-1,400 | Varmint hunting |
| .308 Winchester | 150-180 | 2,700-2,900 | 2,600-3,000 | Big game hunting |
| .50 BMG | 650-750 | 2,800-3,000 | 13,000-15,000 | Long-range, anti-materiel |