Enter any two of distance, duration and pace, and get the third. Free, in kilometres or miles, for a 5K through to a marathon.
Distance, duration and pace are three views of one run. Give the calculator any two of them and it returns the third, along with the average speed.
The three relations are the same relation, rearranged:
pace = duration / distance
duration = distance * pace
distance = duration / pace
The unit you choose applies to the whole result. In kilometers the pace is minutes per kilometer and the speed is km/h. In miles it is minutes per mile and mi/h.
A duration and a pace are typed on a clock, as MM:SS or as HH:MM:SS. Minutes and seconds must be below 60, and the total must be above zero. 30 on its own is refused, because the calculator cannot tell 30 minutes from 30 seconds and does not guess. Write 30:00.
The calculation assumes one constant pace across the whole distance, and the result says so. A distance is shown to two decimal places, a time to the nearest second, and a speed to two decimal places.
The pace is 05:15 per km and the average speed is 11.43 km/h.
The same run reads the other way round. Ask for the duration of 10 km at 05:15 per km, and the answer is 52:30.
Enter 42.195 km and a pace of 05:45, and ask for the duration. The result is 4:02:37, at an average speed of 10.43 km/h.
Thirty seconds a kilometer slower, at 06:15, the same marathon takes 4:23:43. Half a minute per kilometer is worth about 21 minutes across the distance.
Ask for the pace, enter 42.195 km and a duration of 4:00:00. The answer is 05:41 per km, which is an average speed of 10.55 km/h.
Ask for the distance. At 06:30 per km for 45:00 the answer is 6.92 km. At 05:00 per km for 1:00:00 it is 12.00 km.
Use MM:SS for anything under an hour and HH:MM:SS above it. One hour and five minutes is 1:05:00. Minutes or seconds of 60 or more are refused, so 05:99 returns an error rather than a result.
Yes. Choose miles, and the distance, the pace and the speed all follow. Five miles in 40:00 gives a pace of 08:00 per mi and an average speed of 7.50 mi/h.
The result shows it. A pace of 05:00 per km is 12.00 km/h, and 05:45 per km is 10.43 km/h. Pace and speed are the same fact inverted, since one is time over distance and the other is distance over time. To take that speed into knots, feet per second or any other unit, use the Speed Converter.
No. There is no account and no server call. Nothing you type leaves the browser, nothing is saved, and every field returns to its default when you reload the page. The tool also works with no internet connection after your first visit.
The standard distances are longer than their round numbers. A marathon is 42.195 km and a half marathon is 21.0975 km, and a half at 05:45 per km takes 2:01:19. Entering 42 instead of 42.195 gives 4:01:30 rather than 4:02:37, so the last 195 meters are worth 01:07 at that pace.
A pace lost early has to be paid back in full. Run the first half of that marathon 30 seconds a kilometer slow, at 06:15, and it takes 2:11:52. The second half at 05:15, thirty seconds fast, takes 1:50:46. The two add to 4:02:38, within a second of the even 4:02:37, and the odd second is rounding.
To convert a distance between miles and kilometers before you start, use the Length Converter.