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Time Dilation Calculator

Find how time slows for a fast-moving observer.

Inputs

Results

Lorentz factor γ1.666667
Dilated time1.666667years

Chart

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How to use the time dilation calculator

Find how time slows for a fast-moving observer. Enter speed as fraction of c, proper time in the fields above; the lorentz factor γ, dilated time are computed instantly and plotted on the chart so you can see how the answer changes.

Formula

Lorentz factor γ = 1 / √(1-v × v)
Dilated time (years) = t0 × [Lorentz factor γ]

Variables

  • v — Speed as fraction of c
  • t0 — Proper time (years)

Worked example

With speed as fraction of c = 0.8, proper time = 1 years, the calculator gives lorentz factor γ ≈ 1.666667; dilated time ≈ 1.666667 years.

Frequently asked questions

What is the formula for the time dilation calculation?

Lorentz factor γ = 1 / √(1-v × v). Dilated time (years) = t0 × [Lorentz factor γ]. Here v is speed as fraction of c, t0 is proper time (years).

What inputs do I need for the time dilation calculator?

You need speed as fraction of c, proper time in years. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.

How do I use this calculator?

Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.

Is the result exact?

Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.

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