Lorentz Factor (Special Relativity) Calculator

Calculate the Lorentz factor γ for any velocity and find time dilation and length contraction.

⚡ Physics📐 γ = 1/√(1 - v²/c²)
Velocity as fraction of c (0-0.9999)
Or velocity in m/s (or 0)
Please enter valid values.

Formula & Reference

VariableFormulaUnits
Lorentz Factor (Special Relativity) Calculatorγ = 1/√(1 - v²/c²)γ (gamma)

Step-by-Step Examples

Example 1
10% Speed of Light

v = 0.1c.

  • γ = 1/√(1-0.01) = 1.005
  • Barely relativistic
✓ γ = 1.005
Example 2
90% Speed of Light

v = 0.9c.

  • γ = 2.294 | Time 2.3× slower | Length 43% of rest
✓ γ = 2.294
Example 3
99.99% c

v = 0.9999c.

  • γ = 70.7 | Cosmic ray muons reach Earth via time dilation!
✓ γ = 70.7

Real-World Applications

Common Mistakes to Avoid

⚠️
Effects only near c

Significant above ~10% c, but technically exist at any speed. GPS satellites need relativistic corrections.

⚠️
Time dilation direction

The traveler ages LESS — moving clocks run slow.

Frequently Asked Questions

Cosmic ray muons? ▾
Created at ~0.999c, half-life 2.2 μs should decay in 660m, but γ≈22 extends life — they reach Earth's surface.
GPS and relativity? ▾
Satellites: -7 μs/day (SR time dilation) + 45 μs/day (GR, weaker gravity) = net +38 μs/day correction needed.
Mass at relativistic speeds? ▾
Relativistic mass m_rel = γm₀ increases. That's why you can't reach c — it takes infinite energy.

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