How to use the length contraction calculator
Find how length shrinks at relativistic speeds. Enter speed as fraction of c, proper length in the fields above; the contracted length is computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- v — Speed as fraction of c
- L0 — Proper length (m)
Worked example
With speed as fraction of c = 0.6, proper length = 100 m, the calculator gives contracted length ≈ 80 m.
Frequently asked questions
What is the formula for the length contraction calculation?
Contracted length (m) = L0 × √(1-v × v). Here v is speed as fraction of c, L0 is proper length (m).
What inputs do I need for the length contraction calculator?
You need speed as fraction of c, proper length in m. 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.