Calculate pace, time or distance
Running pace is elapsed time divided by distance. Enter a distance and finish time to get an average pace and checkpoint splits. Use kilometres or miles consistently: one mile is 1.609344 km.
Worked 10K example
For a 50-minute 10K, enter 10 km and 00:50:00. The average is 5:00/km, or approximately 8:03/mile. At an even average, the 2 km, 5 km and 8 km checkpoints are 10:00, 25:00 and 40:00. These are cumulative elapsed times, not the time for each separate segment.
Changing the split interval changes the checkpoint spacing, not the finish time. A final partial interval should cover only the remaining distance. Rounding each displayed split can create a small difference if you add rounded values manually.
Pace is not speed
Minutes per kilometre gets smaller as you run faster; kilometres per hour gets larger. A pace of 5:00/km equals 12 km/h. Convert minutes and seconds before dividing: 5:30 is 5.5 minutes, not 5.30 minutes.
Use elapsed time for a race plan
Pausing a watch at an aid station may improve the displayed moving pace, but the official race clock continues. Use elapsed time for finish planning and account for any stops. GPS error, weaving, the measured course line and rounded distance can also make watch pace differ from official splits.
This calculator performs arithmetic. It does not measure fitness, select a sustainable effort or adjust for hills, heat, wind or fatigue. Use the race-time predictor to explore a different distance with explicit assumptions, and the marathon pacing guide to plan execution. Easy training should still reflect an appropriate effort rather than a calculator target.