Running pace is time per distance: minutes per kilometre or minutes per mile. It is the number runners actually train by, because it tells you how fast to run each kilometre, while speed in kilometres per hour tells you how far you go in an hour, which is less useful mid-run. Pace, speed, distance, and time are linked by two equations, and every pace chart, race prediction, and training target is those equations applied repeatedly. This guide works them, converts between per-kilometre and per-mile pace, and shows how to set a race-day target from a known pace. It covers generic pace for any distance; marathon-specific charts are a separate guide on this site.

The two equations

Run 10 kilometres in 50 minutes and your pace is 50 divided by 10, which is 5 minutes per kilometre. Your speed is 10 divided by five sixths of an hour, which is 12 kilometres per hour, matching the shortcut: 60 divided by 5 is 12. Run a mile in 8 minutes and your pace is 8 minutes per mile, your speed is 60 divided by 8, which is 7.5 miles per hour.

The reciprocal relationship is why pace feels counterintuitive at first: a smaller pace number means faster running, while a larger speed number means faster running. A pace of 4:30 per kilometre is faster than 5:30 per kilometre, and the speed figures, 13.3 and 10.9 kilometres per hour, run the other way. The calculator on this site converts between pace, speed, distance, and time in either unit system.

Converting per kilometre and per mile

One mile is 1.609 kilometres, so per-mile pace is per-kilometre pace multiplied by 1.609, and per-kilometre pace is per-mile pace divided by 1.609. A pace of 5:00 per kilometre is 5 times 1.609, which is 8.047 minutes per mile, or 8:03 per mile. A pace of 8:00 per mile is 8 divided by 1.609, which is 4.972 minutes per kilometre, or 4:58 per kilometre.

Speed converts by the same factor in reverse: 12 kilometres per hour is 12 divided by 1.609, which is 7.46 miles per hour, and 7.5 miles per hour is 12.07 kilometres per hour. The commonest conversion error is converting pace as if it were speed: multiplying a per-kilometre pace by 1.609 gives per-mile pace, but multiplying a kilometre-per-hour speed by 1.609 gives the wrong direction. Pace and speed convert oppositely, because they are reciprocals.

Race-day targets from a known pace

If you can hold 5:00 per kilometre, your race times follow by multiplication: 5 kilometres in 25:00, 10 kilometres in 50:00, a half marathon, 21.0975 kilometres, in 1:45:29, and a marathon, 42.195 kilometres, in 3:30:59. Those are even-pace predictions, and real races rarely run evenly: most runners start fast, slow in the middle, and finish with whatever remains, so an even-pace target is a plan to follow, not a prediction to trust blindly.

To set a target from a recent race, work backwards: divide your race time by the race distance to get your demonstrated pace, then apply that pace to the new distance, with a small adjustment for the fact that pace usually slows as distance grows. A 25:00 5K runner does not automatically run a 50:00 10K; the longer race costs a few seconds per kilometre, and prediction formulas that account for that exist, but the simple multiplication is the honest starting point and the chart on this site shows it for every standard distance.

Training paces: easy, tempo, and intervals

Training uses pace zones, not a single pace. Easy running is typically 60 to 90 seconds per kilometre slower than race pace: conversational, sustainable for a long time, and the bulk of most training weeks. Tempo running is near the fastest pace sustainable for about an hour, roughly 10K to half-marathon race pace for most runners. Interval running is faster still, in short repetitions with recovery, at paces from 5K pace down to mile pace or faster.

The zones matter because they train different systems: easy running builds aerobic capacity, tempo builds lactate threshold, intervals build speed and economy. Running every session at race pace trains none of them well and invites injury, which is why the easy days must genuinely be easy, whatever the watch says about the average.

Splits: the average that is not an average

A common error is averaging split paces by adding them and dividing by the count. That works only if every split covers the same distance. If splits cover different distances, the true average pace is total time divided by total distance, never the simple average of the split paces. A 5-kilometre split at 5:00 per kilometre and a 10-kilometre split at 6:00 per kilometre give a total time of 25 plus 60, which is 85 minutes over 15 kilometres, for a true average of 5:40 per kilometre, not the 5:30 the simple average suggests.

The calculator splits tool handles this correctly, and it is worth checking any watch or app average the same way when splits are uneven. For even splits the two methods agree, which is why the error hides so well.

Frequently asked questions

How do you calculate running pace?

Divide time by distance. 50 minutes for 10 kilometres is 5 minutes per kilometre. Speed is the reciprocal: 60 divided by pace in minutes gives kilometres or miles per hour.

How do I convert pace per kilometre to pace per mile?

Multiply by 1.609. 5:00 per kilometre is 8:03 per mile. Divide per-mile pace by 1.609 to go the other way.

What is my race time at 5:00 per kilometre?

5K in 25:00, 10K in 50:00, half marathon in about 1:45:29, and marathon in about 3:30:59, at perfectly even pace.

What pace should easy runs be?

Typically 60 to 90 seconds per kilometre slower than race pace: conversational and sustainable. Easy days must genuinely be easy.

Why is my average pace not the average of my splits?

Because split paces average simply only when splits cover equal distances. True average pace is always total time divided by total distance.

Is pace or speed better for training?

Pace, for most runners, because it tells you how fast to run each kilometre mid-run, while speed tells you distance per hour, which is harder to use on the road.