Running pace calculator
Calculate your running pace, finish time or distance, predict race times from 5K to marathon and get your split times, in miles or kilometres.
Your run
Choose the value to calculate, then enter the other two: the result updates as you type.
Calculate
Your result
Pace
Summary
- Distance
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- Time
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- Pace per kilometre
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- Pace per mile
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- Average speed
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Predicted race times
- 5K
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- 10K
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- Half marathon21.098 km
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- Marathon42.195 km
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Riegel’s formula applied to this run. Beyond the half marathon it often promises recreational runners a time that is too fast.
Split times
Cumulative time at an even pace, at every kilometre or mile (every 5 or 10 over very long distances).
| Distance | Cumulative time |
|---|
Method & sources
Any two of distance, time and pace give the third: pace = time ÷ distance. Speed follows from it (60 ÷ pace in minutes). Predicted race times apply Riegel’s formula to the calculated run, and split times assume an even pace from start to finish.
Formula
Pace = time ÷ distance · Speed = 60 ÷ pace (in minutes) · Riegel: T2 = T1 × (D2 ÷ D1)^1.06Limitations
- Riegel fitted his formula on world records, for efforts of about 3.5 to 230 minutes; outside that range the prediction is flagged as a rough estimate.
- For the marathon it often underestimates recreational runners’ times by 10 minutes or more, especially from a 5K or a 10K.
- Hills, wind, heat and how well you trained for the target distance change the real finish time.
- One mile is 1.609344 km; a half marathon is 21.0975 km (13.1 miles) and a marathon 42.195 km (26.2 miles).