Relativistic Energy Calculator
Calculate energy and momentum for particles moving at relativistic speeds
Energy
Rest Energy E₀ = mc²
0.511059 MeV
8.1872e-14 J
Total Energy E = γmc²
0.542106 MeV
8.6845e-14 J
Kinetic Energy K = E - mc²
0.031046 MeV
4.9736e-15 J
Momentum & Velocity
Momentum p
0.180822 MeV/c
9.6624e-23 kg m/s
Velocity
1.0000e+8 m/s
β = v/c
0.333555704
Lorentz Factor γ
1.060749
Comparison & Invariants
Classical KE (½mv²)
4.5545e-15 J
Relativistic/Classical Ratio
1.0920×
√(E² - p²c²) = mc²
8.1872e-14 J
About Relativistic Energy
Einstein's famous equation E = mc² shows that mass and energy are equivalent. For a moving particle, the total energy is E = γmc², where γ is the Lorentz factor. The energy-momentum relation E² = (pc)² + (mc²)² is Lorentz invariant and holds in all reference frames. At low velocities, the kinetic energy approaches the classical ½mv².