Result
All calculations run locally in your browser: parsing, chart, export. Disconnect the network and the page keeps working.
Facts and limits of this method
| Base unit | Meter per second — all other units convert through it |
|---|---|
| 1 km/h | ≈0.277778 m/s (1000/3600) |
| 1 mph | 0.44704 m/s (exact definition via the international mile) |
| 1 knot | 0.5144444... m/s (1 nautical mile per hour, 1852 m / 3600 s) |
| Total units | 5 — m/s, km/h, mph, knots, ft/s |
When it misleads you
- The calculation happens in two steps: the value is first converted to meters per second, then from meters per second to the target unit, so choosing the same unit for "from" and "to" leaves the result unchanged.
- A knot (nautical mile per hour) is used in aviation and shipping and isn't the same as a regular mile per hour (mph) — these are different units with different factors.
- The converter doesn't account for relative speeds (such as speed relative to a moving medium like wind or current) — it's a purely arithmetic unit conversion of the same speed.
- Rounding is applied only to the displayed result — internal calculations use the full precision of JavaScript floating-point numbers.
How it is calculated
Each of the five units has a preset conversion factor to meters per second — for example, 1 km/h ≈ 0.277778 m/s, 1 knot ≈ 0.514444 m/s.
The entered value is multiplied by the factor of the selected "from" unit, giving speed in meters per second.
The speed in meters per second is divided by the factor of the "to" unit, giving the result in the target unit.
The result is rounded to the chosen number of decimal places and updates instantly whenever the value, units or precision change.
Questions and answers
How is a knot different from a mile per hour?
A knot is a nautical mile per hour (1852 m/h), while mph is a statute mile per hour (1609.344 m/h); a knot is about 15% larger than mph for the same numeric value.
How do I convert km/h to m/s?
Divide the km/h value by 3.6 — that's the same as using this converter with "from" km/h and "to" m/s.
Is this suitable for calculating wind speed?
Yes, for converting the numeric speed value between units — but it doesn't account for wind direction or other meteorological adjustments.
Is my data sent anywhere?
No, the whole calculation runs in your browser.