Pace Calculator
Pace is the runner's native unit: minutes and seconds per kilometre, the number you watch tick by on your watch at each split. Enter any distance and elapsed time and this calculator works out your pace and speed, then extrapolates the same rhythm across the classic race distances. It is equally useful for checking whether a target marathon pace is realistic and for turning a vague want into an exact split to hold.
Enter values
Results
- Pace per kilometre
- 5:00 /km
- Speed
- 12 km/h
- 5K at this pace
- 25:00
- 10K at this pace
- 50:00
- Half / full marathon
- 1:45:29 · 3:30:59
How is the Pace calculated?
Pace is simply time divided by distance, expressed as minutes and seconds for each kilometre. Speed is the same relationship inverted: distance over time in hours, giving kilometres per hour. From there the calculator multiplies your pace by each standard distance, five kilometres, ten, the twenty one point one kilometre half marathon and the forty two point two kilometre marathon, and formats the totals as clock times.
Formula
Pace (min/km) = time (min) ÷ distance (km). Speed (km/h) = distance ÷ time in hours. Finish time = pace × distance. Seconds per kilometre = (total seconds ÷ distance), formatted as m:ss.
Example
Running 10 km in 50 minutes gives a pace of 50 ÷ 10 = 5:00 per kilometre and a speed of 10 ÷ (50 ÷ 60) = 12 km/h. Holding that rhythm, a 5 km takes 25:00 and a 10 km stays 50:00. The half marathon, 21.1 km, comes out at 1:45:29 and the full 42.2 km marathon at 3:30:59. Half a minute per kilometre quicker would trim roughly fourteen minutes from the marathon alone.
Things to remember
Recalculate after each block of work, because the pace that felt heroic in spring often becomes the warm-up in autumn. Keep the numbers handy, but let effort decide the day, especially in heat or on hills where the clock will always flatter nothing.
Frequently Asked Questions
How is pace calculated from distance and time?
Divide your elapsed time by the distance covered and the result is minutes per kilometre. Fifty minutes over ten kilometres gives five minutes per kilometre, and the seconds fall out of the remainder when you convert everything to seconds first.
What is a good running pace for beginners?
There is no universal good pace, since fitness, age and terrain all shift the numbers, but beginners often start between six and nine minutes per kilometre for short runs. The more useful test is conversational speed: if you can speak in sentences you are running the easy pace that builds the aerobic base.
How do I convert pace to speed and back again?
Speed in kilometres per hour is sixty divided by your pace in minutes per kilometre, so a five-minute pace equals twelve kilometres per hour. Reverse it by dividing sixty by the speed. Treadmills often show one unit while watches show the other, and this conversion lets you match them without mental arithmetic mid-run.
Can this calculator predict my marathon time?
It projects your current pace across the full distance, which is a useful first estimate if you have already run something close to the marathon in training. Long distances usually cost a little time per kilometre, so treat the projection as optimistic until your long runs confirm it.
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