Calculate your running pace, finish time, or distance instantly. Get race time predictions for 5K, 10K, half marathon, and marathon. Supports km and miles. Free and offline.
Added May 13, 2026
Input
In the unit selected above.
Result
Enter a value for calculate to see your result.
Calculates running pace, finish time, or distance from any two known values. Also predicts finish times for common race distances (5K, 10K, half marathon, marathon) at the given pace.
Pace = Time ÷ Distance | Time = Pace × Distance | Distance = Time ÷ Pace
Pace = 25 min ÷ 5 km = 5:00 /km, equivalent to 12.0 km/h.
Inputs
Result
Time = 5.5 min/km × 42.195 km = 232.07 min ≈ 3:52:04.
Inputs
Result
Running pace is the time it takes to cover one unit of distance — usually expressed as minutes per kilometer (min/km) or minutes per mile (min/mi). A pace of 5:00 /km means you run one kilometer every five minutes.
Divide your total finish time by the distance. For a 5K finished in 25:00, pace = 25 min ÷ 5 km = 5:00 /km. This calculator does that automatically — select 'Pace', enter your distance and time, and read the result.
A sub-4 hour marathon (42.195 km) requires a pace of about 5:41 /km or 9:09 /mi. Select 'Pace', enter 42.195 km (or 26.22 miles) and a time of 4:00:00 to see the exact target pace.
They assume a perfectly even effort at the same pace for the full distance. Real races involve warm-up, fatigue, course elevation, and pacing variation, so treat predictions as targets rather than guarantees.