Running pace calculator
Pace per km and per mile from distance and time.
How it works
Pace is time divided by distance. One mile is 1.609 km.
How to read your result
The result is your average pace: how long one kilometre or one mile takes you, in minutes and seconds. A lower number is faster. The page rounds to the nearest second.
It is an average over the whole distance. It cannot show how each kilometre went, so a fast start and a slow finish can give the same number as a steady run. Weather matters too: a study of marathon results found a progressive slowing of performance as the wet-bulb globe temperature rose from 5 to 25 °C. A pace from a cool day will not carry over to a hot one.
Use the number as a target. A review of pacing research found that in events longer than 2 minutes, times may improve when athletes spread their pace more evenly. Pace tells you how fast, not how hard. For effort, try the talk test: at moderate effort you can talk but not sing, and at vigorous effort you cannot say more than a few words without pausing for breath. In the Zefro app, a run shows pace per kilometre or per mile, with a split for every kilometre or mile.
A worked example
Say you run 10 km in 50 minutes (0:50:00). Step 1: 50 minutes × 60 = 3000 seconds. Step 2: 3000 seconds ÷ 10 km = 300 seconds per km, which is 5:00 per km. Step 3: for miles, 300 × 1.609344 = 482.8 seconds, which is 8 minutes 2.8 seconds, shown as 8:03 per mile. If you enter about 6.2137 miles instead of 10 km, the page converts it to km first and gives the same answer.
A half marathon is 21.0975 km (13.1 miles). Run it in 1:40:00 and the sum is: 1 hour 40 minutes = 6000 seconds. 6000 ÷ 21.0975 = 284.4 seconds per km, shown as 4:44 per km. 284.4 × 1.609344 = 457.7 seconds, shown as 7:38 per mile.
How do I calculate running pace?
Divide your time by your distance. 50 minutes for 10 km is 3000 seconds ÷ 10 = 300 seconds, so 5:00 per km. Enter the distance and time above and the page does it for you.
How do I convert pace per km to pace per mile?
Multiply the pace per km by 1.609344, because a mile is exactly 1.609344 km. 5:00 per km is 300 × 1.609344 = 482.8 seconds, or 8:03 per mile. To go back, divide: 8:00 per mile is 480 ÷ 1.609344 = 298.3 seconds, or 4:58 per km.
What pace do I need for a 4-hour marathon?
A marathon is 42.195 km (26.2 miles). 4:00:00 is 14400 seconds, and 14400 ÷ 42.195 = 341.3 seconds, so about 5:41 per km or 9:09 per mile.
Should I run the whole race at the same pace?
Mostly, yes. A review of pacing research found that in events longer than 2 minutes, times may improve when athletes spread their pace more evenly. Heat can slow you: marathon times slowed steadily as the temperature rose.