Convert speeds across road, science, and marine units.
How it works
- Select the initial speed metric and your desired converted metric.
- Enter the speed value.
- The calculator maps the value via meters per second to give you an exact speed.
Frequently asked questions
km/h to mph quick rule?
Multiply by 0.62 — 100 km/h ≈ 62 mph.
Why do ships and planes use knots?
Nautical miles tie to degrees of latitude, making navigation math cleaner.
What is a fast sprint in these units?
Elite sprinters peak near 12 m/s ≈ 43 km/h ≈ 27 mph.