How to calculate running pace and finish time

Pace is time divided by distance. Running 5 km in 25 minutes is 25 ÷ 5 = 5 minutes per kilometre, written 5:00/km.

Enter times with seconds as decimals: 25 minutes 30 seconds is 25.5 minutes, giving a pace of 5.1 minutes per km, or 5:06.

Multiply the pace by the distance. A 10 km race at 5:00/km finishes in 50 minutes. A half marathon, 21.0975 km, at 5:30/km takes about 1 hour 56 minutes.

A marathon, 42.195 km, at 6:00/km is 253.17 minutes, or 4 hours 13 minutes 10 seconds.

One mile is 1.609344 km. To convert a pace per kilometre to a pace per mile, multiply by 1.609. A 5:00/km pace is about 8:03 per mile.

To go the other way, divide a pace per mile by 1.609.

Run easy runs slower than your race pace and save the target pace for specific workouts. Starting a race too fast is the most common reason for slowing late.

Use the pace calculator after a run to see your average, and compare it with your goal to plan the next training block.