Pace calculator
The race times below are the same pace extended to longer distances, which is not how running works — everyone slows as distance rises. Riegel formula projections raise the pace by about six per cent per doubling of distance, so a 50-minute 10K predicts a marathon nearer 3:52 than the 3:31 a flat extrapolation gives. Treat these rows as a floor, not a forecast.
Pace is time divided by distance. Ten kilometres in 50 minutes is a pace of 5:00 per kilometre, or 8:03 per mile, at 12 km/h. Any two of pace, time and distance give the third.
How to calculate running pace
Converting between minutes per kilometre and minutes per mile trips people up because it is not a division you can do in your head reliably: a 5:00/km pace is 8:03/mile, not 8:00. The mile is 1.609 kilometres, so a mile pace is always the kilometre pace times 1.609. Speed in km/h is the other useful view, and the one treadmills use — a 5:00/km pace is exactly 12 km/h, which is a rare case where the arithmetic is clean.
Questions
Divide total time by distance. Fifty minutes over 10 km is 5:00 per kilometre.