Running Pace Converter

Speed in km/h is 3600 divided by the seconds per kilometre. A 5:00 per km pace is 300 seconds, so 3600 divided by 300 gives exactly 12 km/h. The mph value is that km/h figure divided by 1.609344.

Multiply the per-km seconds by 1.609344 to get seconds per mile. So 300 seconds becomes about 482.8 seconds, which rounds to 8:03 per mile. The tool does this conversion automatically alongside the speeds.

One mile is exactly 1.609344 kilometres, and that is the constant used for every pace and speed conversion here. Using the full precise value rather than a rounded 1.6 keeps mile and kilometre figures consistent across long distances.

Yes. Choose km/h or mph as the input unit and type a plain decimal number, and the tool returns the matching pace per km and per mile plus the other speed. This is ideal for reading a treadmill dial and translating it into an outdoor pace.

For pace units you can type minutes and seconds as m:ss or mm:ss, such as 8:03, and the seconds part must be 00 to 59. A bare number of seconds also works. Results are always shown as minutes and seconds, rounded to the nearest whole second.

Pace and speed must be positive, so zero or negative numbers are refused, and a malformed time like 5:75 fails because 75 is not a valid seconds value. Clearing the box simply shows no result rather than an error.

Slightly, yes. Paces are rounded to the nearest second and speeds are shown to two decimals, so converting a value out and back can shift the last digit. The underlying math keeps full precision; only the display is rounded.

Yes. Convert your goal pace to speed to set a treadmill, or convert a known finish speed to pace to plan splits. For a full finish-time estimate across a race distance, pair it with a distance and time calculator, since this tool converts pace and speed rather than total time.

Yes. Every conversion runs in your browser with no network calls, so the paces and speeds you enter never leave your device.