A pace calculator works out how fast you need to run each kilometre or mile from a distance and a finish time. A 5 km run in 30 minutes is a pace of 6:00 per km, or 9:39 per mile, at 10 km/h; a 4-hour marathon needs 5:41 per km.
On this page
How to use the pace calculator
- Enter the distance and choose kilometres or miles.
- Enter the time in hours, minutes and seconds.
- Read the pace per unit and the average speed.
- Change the time to test different race goals.
What formula does the pace calculator use?
- Pace = total time ÷ distance, shown as minutes:seconds per kilometre or per mile
- Speed = distance ÷ time in hours
- 1 mile = 1.609344 km exactly, so pace per mile = pace per km × 1.609344
Pace calculator worked example
| Race and time | Pace per km | Pace per mile | Speed |
|---|---|---|---|
| 5 km in 30:00 | 6:00 | 9:39 | 10.0 km/h |
| 10 km in 55:00 | 5:30 | 8:51 | 10.9 km/h |
| Half marathon (21.0975 km) in 2:00:00 | 5:41 | 9:09 | 10.5 km/h |
| Marathon (42.195 km) in 4:00:00 | 5:41 | 9:09 | 10.5 km/h |
The calculator rounds pace to the nearest whole second, so 4:59.6 per km is shown as 5:00.
Standard race distances
| Race | Kilometres | Miles |
|---|---|---|
| 5K | 5 | 3.107 |
| 10K | 10 | 6.214 |
| Half marathon | 21.0975 | 13.109 |
| Marathon | 42.195 | 26.219 |
A marathon is 42.195 km, the distance used by World Athletics, and a half marathon is exactly half of that.
Finding a finish time from a goal pace
Multiply your goal pace by the distance. At 5:30 per km, a 10K takes 55 minutes and a half marathon about 1:56:02. To aim for a time, enter the distance and goal time in the pace calculator and run at the pace it shows, starting a little slower and finishing a little faster if you can.
Treadmill speed to pace
Treadmills show speed, not pace. To convert, divide 60 by the speed: 12 km/h is 5:00 per km, 10 km/h is 6:00 per km and 8 km/h is 7:30 per km. For a treadmill set in miles per hour, 6 mph is 10:00 per mile and 7.5 mph is 8:00 per mile.
Even pacing and negative splits
Many runners lose time by starting too fast. Running the second half at the same speed as the first, or slightly faster (a negative split), usually gives a better finish time for the same effort. Break a long race into sections and check your split at each kilometre or mile marker against the target pace.
Using pace in training
- Easy runs are usually much slower than race pace; you should be able to talk.
- Hills, heat, wind and trails slow your pace, so compare effort, not just numbers.
- GPS watches can be off on tracks, in cities and under trees; a measured course or a 400 m track is more reliable.
For general fitness, U.S. guidelines advise adults to get at least 150 minutes of moderate activity or 75 minutes of vigorous activity a week.
Estimates for planning only. Check important figures with an official source or a qualified professional.
Planning pace for race day
Use the pace calculator to turn a goal time into a pace you can check at each marker. Many runners write their target splits on a wristband or set a pace alert on their watch. GPS watches can drift from the course measurement, especially in cities with tall buildings or under trees, so the official kilometer or mile markers are a more reliable check than the watch distance.
Courses are measured along the shortest possible route, so if you run wide around corners and weave through other runners, you will cover more distance than the race length. Allow for that by aiming a few seconds per kilometer faster than the pace calculator figure for your goal. Hills, heat and wind also slow you down, so adjust your target pace on difficult days rather than forcing the plan. A steady effort usually beats a fast start followed by a hard finish. After the race, compare your actual splits with the plan to set a better target next time.
Related converters and calculators
Related calculators:
- Calories burned calculator: energy
- Target heart rate calculator: training zones
- Speed calculator: speed
- Km to miles: distance
Sources
NIST: Length units and the mile; World Athletics; Physical Activity Guidelines for Americans.
Questions about this calculator
How do I calculate running pace?
Divide your total time by the distance; 30 minutes for 5 km is 6:00 per km.
What pace is a 4-hour marathon?
About 5:41 per km or 9:09 per mile.
How long is a marathon?
42.195 km, or about 26.2 miles.
How do I convert pace per km to per mile?
Multiply by 1.609344.
Why does my watch show a different pace?
GPS error, pauses and auto-lap settings can change the figure.
Check the assumptions and units before relying on a result. Financial, tax and health estimates do not replace advice for your individual circumstances.
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