How to use the pace calculator
- Choose what to work out: your pace, your finish time, or the distance you cover.
- Pick kilometers or miles. Pace and splits are shown in the unit you choose.
- Choose a race distance (5K, 10K, half marathon or marathon), or other distance to type your own.
- Enter the time in hours, minutes and seconds, and/or the pace in minutes and seconds per km or mile, depending on what you are working out.
- Read the answer, the even-pace splits and what the same pace means for other race distances.
The pace formula
Pace and speed describe the same thing in two ways. Runners usually think in pace (minutes per km or mile), while treadmills and cyclists often use speed. A pace of 6:00 per km is 10 km/h; 6:00 per km is also 9:39 per mile.
Worked example
The calculator starts with a 10K run in 55 minutes, in kilometers:
- Time in seconds: 55 × 60 = 3,300 s
- Pace: 3,300 ÷ 10 km = 330 s per km = 5:30 per km
- Per mile: 330 × 1.609344 = 531 s = 8:51 per mile
- Speed: 10 km ÷ (55 ÷ 60) h = 10.91 km/h, or 6.78 mph
- Splits: 5:30 at 1 km, 27:30 at 5 km, 55:00 at the finish
- At the same pace, a half marathon would take 21.0975 × 330 s = 1:56:02, and a marathon 3:52:04
For a target time, switch to finish time. A half marathon at 5:00 per km takes 21.0975 × 300 s = 1:45:29.
Pace chart for common goals
| Goal | Pace per km | Pace per mile |
|---|---|---|
| 5K in 30:00 | 6:00 | 9:39 |
| 10K in 50:00 | 5:00 | 8:03 |
| Half marathon in 2:00:00 | 5:41 | 9:09 |
| Marathon in 4:00:00 | 5:41 | 9:09 |
| Marathon in 3:30:00 | 4:59 | 8:01 |
A 2-hour half marathon and a 4-hour marathon need the same pace, but holding it for twice as long is much harder. Race times don't scale evenly with distance: most runners slow down by a few percent each time the distance doubles. So the race-time table in the calculator is an even-pace projection, not a prediction.
Using splits on race day
Even splits, running every km or mile at the same pace, are the simplest plan and close to what most coaches recommend for long races. A slightly faster second half (a negative split) is a sign of good pacing. Going out much faster than your goal pace in the first few kilometers is the most common mistake: it feels easy on fresh legs but often costs more time later than it saved. Hills, heat and wind all slow you down, so allow for them rather than chasing the numbers. If you are new to running or have a heart condition, check with your doctor before starting hard training.
Frequently asked questions
How do I convert pace per km to pace per mile?
Multiply the pace in seconds by 1.609344. For example, 5:00 per km is 300 seconds, and 300 × 1.609344 = 483 seconds, or 8:03 per mile. To go the other way, divide by 1.609344.
How do I turn speed into pace?
Divide 60 by the speed to get minutes per km or mile. A treadmill set to 12 km/h gives a pace of 60 ÷ 12 = 5 minutes per km. At 6 mph, the pace is 10 minutes per mile.
What is a good running pace?
It depends on your age, fitness and the distance. A comfortable pace for easy runs is one where you can still hold a conversation. For many recreational runners that is somewhere between 6 and 8 minutes per km (about 10 to 13 minutes per mile).
Why is my GPS watch distance different?
GPS loses accuracy under trees, between tall buildings and on tight bends, and race courses are measured along the shortest possible line. Most runners record a little more than the official distance, so their watch pace looks slightly faster than their official pace.
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Results are estimates for general information and are not medical advice. Talk to a doctor or other qualified professional about your health. See our disclaimer.