Running pace calculator
Choose what you want to find: pace, time or distance. Enter the other two values and the calculator shows your pace, speed, splits and the times for the standard race distances.
How it is calculated
How running pace is calculated
Pace is the time per kilometre (or per mile): pace = time ÷ distance. The two reverse forms are time = pace × distance and distance = time ÷ pace. Speed is the inverse: km/h (or mph) = 60 ÷ pace in minutes.
Worked example
10 km in 50:00: 3,000 s ÷ 10 km = 300 s per km = 5:00 min/km, i.e. 60 ÷ 5 = 12 km/h. Per mile that is 300 s × 1.609344 = 482.8 s = 8:03 min/mi (7.46 mph). At this pace a marathon takes 42.195 × 300 s = 12,658.5 s ≈ 3:30:59.
Kilometres and miles
One international mile is exactly 1.609344 km (NIST SP 811). A pace of 5:00 min/km therefore equals 8:03 min/mi, and 8:00 min/mi equals 4:58 min/km.
Standard race distances
| Race | Length |
|---|---|
| 5K / 10K | 5 or 10 km (3.107 or 6.214 miles) |
| Half marathon | 21.0975 km (13.109 miles) |
| Marathon | 42.195 km (26.219 miles) |
Splits assume an even pace. The results are a training aid and do not replace medical advice – if you have a health condition, get checked before hard training.
Frequently asked questions
What does pace mean in running?
Pace is the time you need for one kilometre or one mile, e.g. 5:30 min/km. The smaller the number, the faster you run.
How do I convert pace to speed?
Divide 60 by the pace in minutes. 5:00 min/km is 60 ÷ 5 = 12 km/h; 10:00 min/mi is 6 mph.
What pace do I need for a sub-4-hour marathon?
4 hours are 14,400 s; divided by 42.195 km that is 341.3 s, so about 5:41 min/km or 9:09 min/mile.
How do I enter the time?
As minutes:seconds (50:00) or hours:minutes:seconds (1:45:30). With two parts the minutes may exceed 59, e.g. 95:00.
Why do my race splits differ from the table?
The calculator assumes an even pace. The start, hills, wind and aid stations shift your real splits, and GPS watches often measure a little too much distance.
Sources and legal basis
- NIST SP 811: NIST Special Publication 811, Appendix B.8 – mile (international) = 1.609 344 km (exact)
- World Athletics Competition Rules: World Athletics – Book of Rules (Competition Rules, road races: half marathon 21.0975 km, marathon 42.195 km)
As of:
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