โณTime Dilation Calculator
See how time slows down as you approach the speed of light.
Free Time Dilation Calculator
Our free time dilation calculator applies special relativity's time dilation formula, tโฒ = t / ฮณ where ฮณ = 1/โ(1 โ vยฒ/cยฒ), to show how much slower a clock moving at velocity v runs compared to a stationary observer. Enter a velocity as a fraction of the speed of light and an elapsed time, and see the Lorentz factor, the dilated time experienced by the moving observer, and exactly how much time is "lost" between the two frames.
Use the presets to explore everyday and extreme cases โ from the International Space Station's orbital speed, where the effect is a tiny fraction of a second per year, to velocities near the speed of light, where a year for a stationary observer can correspond to just weeks or days for the traveler. The effect only becomes noticeable at a meaningful fraction of light speed, which is why we don't experience it in daily life.
Built for physics students studying special relativity, and for anyone curious about how motion affects the passage of time. No sign-up, no downloads โ just instant results.