Formula
pace = time ÷ distancespeed = distance ÷ timepace per mile = pace per km × 1.609344
- 1 mile = 1.609344 km exactly
- Speed in km/h = 3600 ÷ (seconds per km)
Pace is time per unit distance; speed is its reciprocal.
Worked examples
10 km in 50 minutes
- What do you want to find?
- Pace (from distance and time)
- Distance
- 10
- Distance unit
- Kilometres
- Hours
- 0
- Minutes
- 50
- Seconds
- 0
Pace
5:00 per km · 8:03 per mile
Pace per km: 5:00
Pace per mile: 8:03
Speed: 12 km/h · 7.4565 mph
Marathon finish time at 5:30 per km
- What do you want to find?
- Finish time (from distance and pace)
- Distance
- 42.195
- Distance unit
- Kilometres
- Pace — minutes
- 5
- Pace — seconds
- 30
- Pace is per
- Kilometre
Finish time
3:52:04
Pace per km: 5:30
Pace per mile: 8:51
Speed: 10.9091 km/h · 6.7786 mph
How it works
Pace is how long each kilometre or mile takes, and speed is its reciprocal. If you run 10 km in 50 minutes your pace is 5:00 per km, which is 8:03 per mile and a speed of 12 km/h (about 7.46 mph). Enter any two of distance, time and pace and the third is calculated.
The table at the bottom shows the finish time for common race distances if you could hold exactly that pace throughout: 5K, 10K, 15K, ten miles, the half marathon (21.0975 km) and the marathon (42.195 km). That is simple arithmetic, not a prediction — almost nobody holds a constant pace, and the longer the distance, the more it usually fades.
Pace per kilometre and per mile are linked by the exact definition of the mile, 1.609344 km. For plain speed conversions use the Speed Converter, and for travel problems the Speed, Time and Distance Calculator. To add up split times use the Time Duration Calculator.
Assumptions and limits
- Pace is held constant for the whole distance.
- Times are rounded to the nearest second.