What running pace is
Pace is the time it takes to cover one unit of distance, normally written as minutes and seconds per kilometre or per mile. It is the reverse of speed: a pace of 5:00 per km is a speed of 12 km/h. Runners prefer pace because it is easy to hold in mind while running and maps directly to split times on a watch. This calculator turns a distance and a finish time into pace, and also works backwards from a pace to a finish time.
How the maths works
Pace per kilometre equals total time in seconds divided by distance in kilometres. For 10 km in 52 minutes 30 seconds, that is 3,150 ÷ 10 = 315 seconds, or 5:15 per km. To get pace per mile, multiply by 1.609344: 315 × 1.609344 = 507 seconds, or 8:27 per mile. Speed is distance divided by time in hours, so the same run is 11.43 km/h or 7.10 mph. To find a finish time, multiply pace per kilometre by the race distance.
Equal-pace race table
The table under the first calculator shows what each standard distance would take if you could hold exactly your pace: the mile, 5K, 10K, half marathon (21.0975 km) and marathon (42.195 km). It is a planning aid and not a prediction. Most runners slow down over longer distances, so a 10K pace is rarely sustainable over a full marathon. Use a recent race at a similar distance as a better guide for goal setting.
Using pace in training
- Easy runs are often 1 to 2 minutes per mile slower than race pace, which helps recovery.
- Pacing a race evenly or with a slightly faster second half usually works better than starting too fast.
- Track and treadmill work often uses speed in km/h, so check the speed line in the result.
Good to know
GPS watches can differ from official course distance by a percent or two, so your measured pace may differ from the pace needed to hit a target finish time. The tool does not store data and runs only in your browser.