Pace Calculator
Running pace, time and distance.
Distance
Time
1 mile = 1.609344 km. Pace is minutes per km; speed is how many kilometres you cover in an hour.
Your pace
5:15 /km
10 km in 0:52:30 at 5:15 per km.
| Race | Estimated time | Pace /km |
|---|---|---|
| 5K | 0:25:11 | 5:02 |
| 10K(your effort) | 0:52:30 | 5:15 |
| Half marathon | 1:55:50 | 5:29 |
| Marathon | 4:01:31 | 5:43 |
Estimates using Riegel's formula, T2 = T1 × (D2 ÷ D1)^1.06. They assume similar training and conditions, and real race times will differ.
How to Use the Pace Calculator
This pace calculator turns a distance and a time into your running pace in minutes per km (and per mile), your speed in km/h and mph, and a splits table. It also works the other way: enter a distance and the pace you want to hold to see your finish time, or enter a time and a pace to see how far you'll go. Choose a preset such as 5 km, 10 km, half marathon or marathon, or type in any custom distance.
Whether you think of it as a mins per km calculator, a minute mile calculator or a pace and speed calculator, it is the same relationship between distance, time and speed. Note that “miles per minute” usually means minutes per mile; the results show both pace per mile and speed in mph.
Pace and Speed Formulas
Speed = 60 ÷ pace in minutes = distance ÷ time in hours
Finish time = pace × distance | Distance = time ÷ pace
Per km to per mile: multiply the pace by 1.609344
km/h to mph: divide by 1.609344
T1 and D1 are the time and distance you entered; T2 is the estimated time for the new distance D2. It is an estimate only.
Worked Example: 10 km in 52:30
You run 10 km in 52 minutes 30 seconds, which is 3,150 seconds. Dividing by 10 gives 315 seconds per km, so your pace is 5:15 /km, or 8:27 /mile. Your speed is 11.43 km/h (7.10 mph). With even pacing, the splits table shows 5:15 at 1 km, 10:30 at 2 km and so on to 52:30 at 10 km.
Riegel's formula then estimates (these are estimates only) a 5K in about 25:11 (5:02 /km), a half marathon in about 1:55:50 (5:29 /km) and a marathon in about 4:01:31 (5:43 /km). The marathon figure assumes you have trained for the longer distance.
Worked Example: A Marathon at 5:30 /km
To hold 5:30 per km (330 seconds) over a marathon of 42.195 km, the finish time is 330 × 42.195 = 13,924 seconds, or 3:52:04. That pace is 10.91 km/h (6.78 mph), or 8:51 per mile. You'd pass 10 km in 0:55:00 and the half marathon in about 1:56:02. The split table has 43 rows: 42 full kilometres, then a final partial split of 0.195 km.
Pace and Speed Quick Reference
Handy for treadmills, which usually show km/h while your watch shows minutes per km.
| Pace (min/km) | Speed (km/h) | Speed (mph) |
|---|---|---|
| 3:00 | 20 | 12.4 |
| 3:30 | 17.1 | 10.7 |
| 4:00 | 15 | 9.3 |
| 4:30 | 13.3 | 8.3 |
| 5:00 | 12 | 7.5 |
| 5:30 | 10.9 | 6.8 |
| 6:00 | 10 | 6.2 |
| 6:30 | 9.2 | 5.7 |
| 7:00 | 8.6 | 5.3 |
| 7:30 | 8 | 5 |
| 8:00 | 7.5 | 4.7 |
Splits and Negative Splits
The splits table assumes you hold the same pace for every kilometre or mile, which is a useful reference for race day. If the distance isn't a whole number, the last row is a partial split. Many runners aim for even splits or a slightly faster second half (a negative split), because starting too fast tends to cost time later. The best strategy depends on the course, the weather and how much training you have done.
Limits of Race Predictions
Riegel's formula is a simple curve fitted to how race times grow with distance, and it can't know your training. Predicting a marathon from a 5K usually overshoots what an under-trained runner can hold, while a very short effort (under about three minutes) or a very long one (over about four hours) is outside the range where the formula is most reliable. Treat the numbers as a starting point, ideally cross-checked against a recent race at a similar distance.
Frequently Asked Questions
- How do I use a mins per km calculator?
- Enter the distance you ran and your time in hours, minutes and seconds, and the calculator divides the time by the distance to give your pace in minutes per kilometre. For example, 10 km in 52:30 is 3,150 seconds ÷ 10 = 315 seconds per km, or 5:15 /km. Switch to the miles option if you want the answer per mile instead.
- How do I calculate pace per km by hand?
- Convert your total time to minutes (or seconds) and divide by the distance in kilometres. A 5 km run in 27:30 is 27.5 minutes ÷ 5 = 5.5 minutes per km, which is 5:30 /km because 0.5 of a minute is 30 seconds. Remember that the decimal part is a fraction of 60 seconds, not of 100.
- How do I convert pace to km/h, and km/h to pace?
- Speed in km/h = 60 ÷ pace in minutes per km, and pace in minutes per km = 60 ÷ speed in km/h. A pace of 5:30 /km is 5.5 minutes, so 60 ÷ 5.5 = 10.9 km/h. Going the other way, 12 km/h is 60 ÷ 12 = 5.0 minutes per km, or 5:00 /km. The same pace calculator km/h conversion works for treadmill settings.
- What is a minute mile calculator, and how fast is a 6-minute mile?
- A minute mile calculator works out your pace in minutes per mile, or the pace you need to run a given mile time. A 6:00 mile is 10 mph, which is about 16.1 km/h or roughly 3:44 per km (because 1 mile is 1.609344 km). A 4:00 mile is 15 mph, or about 2:29 per km.
- Is miles per minute the same as minutes per mile?
- No, they are opposites, although people often search for miles per minute when they mean minutes per mile. Minutes per mile is the usual running pace (for example 8:00 per mile). Miles per minute is a speed, so 8:00 per mile is 1 ÷ 8 = 0.125 miles per minute, which is 7.5 mph. This calculator shows pace per mile and speed in mph so you can see both.
- How do I work out average pace for a run with several different speeds?
- Add up the total time and the total distance for the whole run, then divide time by distance. Averaging the paces of each kilometre works when the segments are all the same length, but not when they differ. If you ran 5 km at 5:00 /km and 5 km at 6:00 /km, the total is 55 minutes for 10 km, so the average is 5:30 /km.
- What is a split, and what is a negative split?
- A split is the time for one segment of a run, usually each kilometre or mile, and the splits table shows your time at the end of every kilometre or mile if you hold an even pace. A negative split means you run the second half faster than the first. For a 10 km run in 52:30, running the first 5 km in 26:30 (5:18 /km) and the second in 26:00 (5:12 /km) is a negative split. Even or slightly negative pacing is a common approach, but what works best varies between runners and courses.
- How accurate are the race time predictions?
- They are estimates only. The calculator uses Riegel's formula, T2 = T1 × (D2 ÷ D1)^1.06, which assumes you have trained for the longer distance and race in similar conditions. It tends to be too optimistic when predicting a marathon from a short race, such as a 5K, if your weekly distance is low, and it is less reliable for efforts shorter than a few minutes or longer than a few hours. Hills, heat and pacing will all change your real result.
- What is a good running pace?
- There is no single good pace because it depends on your age, fitness, terrain, the weather and your goal. Beginners commonly start with a comfortable pace and build up gradually, and a pace that is good for you may be quite different from a friend's. A useful check for an easy run is that you can speak in short sentences. If you have health concerns, check with your GP before increasing your training.