Run Race Pace Calculator
Turn a finish time and race distance into pace per mile, pace per kilometer, average speed, and a same-pace finish estimate for another race distance.
Interactive calculator · Method RUN_RACE_PACE-2.0 · Last reviewed: 2026-10-02
Calculate race pace from distance and time
Choose a common race distance or enter your own, then add the finish time you want to compare. The result shows the pace you would need to hold evenly.
Your inputs
Default worked example. Edit the inputs to calculate your scenario.
Default worked example
10 km in 50:00 = 5:00 per kilometer. Projection assumes the same constant pace; it does not predict race performance.
How to use the calculator
Convert distance and elapsed time: choose whether to find pace, finish time or distance. Enter elapsed hours, minutes and seconds with minutes/seconds from 0 through 59. Distance may use a standard event or a measured custom route. Pace input is per kilometer.
What the result means
Splits describe a constant pace. The projected time for another distance assumes that pace continues; it does not predict fitness, terrain, weather or personal race performance.
Formula and units
Pace in seconds/km = elapsed seconds ÷ distance in km. Finish seconds = pace × distance. Distance = elapsed seconds ÷ pace. Mile pace = kilometer pace × 1.609344. Each split multiplies elapsed pace by its distance.
Worked examples
10 km in 50 minutes: Pace minutes per kilometer: 5 minutes per km; Pace seconds (0–59): 0 seconds per km; Custom distance: 6.2 selected distance unit; Finish time hours: 0 hours; Finish time minutes: 50 minutes/seconds; Finish time seconds: 0 minutes/seconds; Custom projection distance: 13.1 selected distance unit; Find: pace; Race distance: 10k; Project the same pace to: half; Custom distance unit: miles; Projection distance unit: miles.
Example result: Pace per kilometer: 5:00 /km; Pace per mile: 8:03 /mi; Finish time used: 50:00; Race distance: 10 km / 6.214 mi; Average speed: 12 km/h; Projected half marathon: 1:45:29.
25-minute 5K: Pace minutes per kilometer: 5 minutes per km; Pace seconds (0–59): 0 seconds per km; Custom distance: 6.2 selected distance unit; Finish time hours: 0 hours; Finish time minutes: 25 minutes/seconds; Finish time seconds: 0 minutes/seconds; Custom projection distance: 13.1 selected distance unit; Find: pace; Race distance: 5k; Project the same pace to: half; Custom distance unit: miles; Projection distance unit: miles.
Example result: Pace per kilometer: 5:00 /km; Pace per mile: 8:03 /mi; Finish time used: 25:00; Race distance: 5 km / 3.107 mi; Average speed: 12 km/h; Projected half marathon: 1:45:29.
Limitations and common mistakes
Splits list the first 100 whole kilometers and the finish for longer routes, keeping computation bounded. Displayed times round to the nearest second; calculations keep the underlying fractional seconds.
A time of 1 hour 30 minutes is 1:30:00, not 1.30 hours. Choose the correct distance unit and distinguish elapsed race time from moving time.
Sources and assumptions
Method RUN_RACE_PACE-2.0; last formula review 2026-10-02. Sources and their supported claims. Calculation methodology.