What this calculator does
Time dilation works out how much slower a clock moving at speed v runs, compared to a stationary observer. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formulat = t₀/√(1−v²/c²) (special relativity, c = 299,792,458 m/s)
The inputs explained
| Field | What to enter |
|---|---|
| Proper time elapsed (moving clock) (s) | A number, measured in s. Starts at 1. |
| Relative speed (m/s) | A number, measured in m/s. Starts at 150000000. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with proper time elapsed (moving clock)
Every other input is held at the calculator’s starting values while proper time elapsed (moving clock) varies. Select any row to load that scenario into the calculator.
How the answer changes with proper time elapsed (moving clock)