Speed Distance Time Calculator — Free Online Tool
Solve for any one of speed, distance or time — with km/h, m/s and mph/miles unit conversion handled for you, instantly in your browser.
Speedanswer
enter values above and press Calculate
v = d ÷ t
km/h · m/s · mph
No sign-up needed
Free forever
How it works
1Pick what to solve — speed, distance or time.
2Enter the other two with their units — mixing km and miles is fine.
3Press Calculate — the answer appears in your chosen unit, plus all others.
Frequently asked questions
What formulas does this tool use?
The classic trio: speed = distance ÷ time, distance = speed × time, and time = distance ÷ speed. Every calculation is done in SI units internally and then converted to your chosen output unit.
How do I convert 50 km/h to m/s?
Divide by 3.6: 50 km/h = 13.89 m/s. Solve-for-speed mode shows your answer in km/h, m/s and mph automatically. Conversely, multiply m/s by 3.6 to get km/h.
Can I mix miles with hours, or metres with seconds?
Yes — every input and the output has its own unit selector. 1 mile = 1609.344 metres exactly, and the tool converts consistently before applying the formula.
v = d/t · km/h · m/s · mph/miles · 100% local — your numbers never leave this page.