Running Pace Calculator
Find your running pace, speed, finish time, or distance — in min/km or min/mile — and see the equivalent speed.
Equivalent speed: 12 km/h · 7.46 mph.
Running pace is time ÷ distance. Run 10 km in 50:00 and your pace is 3000 s ÷ 10 km = 300 s/km, which is 5:00 per kilometre. That same effort is a speed of 12 km/h (7.46 mph). At 5:00 /km a marathon (42.195 km) takes about 3:30:59.
What running pace is
Pace is how long it takes to cover one unit of distance — minutes per kilometre or minutes per mile — and it is the number most runners train and race by. It is the inverse of speed (distance per unit of time): a lower pace means a faster run, while a higher speed means the same thing. Splitting a run into pace makes it easy to check progress at every kilometre marker instead of doing mental arithmetic on speed.
Any two of the three quantities — distance, time, and pace — fix the third. Know your distance and finish time and you can find pace; know your goal pace and a race distance and you can predict the finish time; know how long you ran and at what pace and you can back out the distance. This calculator solves for whichever one you leave blank and converts between kilometres and miles for you.
Pace is time per unit distance (min/km or min/mi); speed is its inverse (km/h or mph).
Worked example: 10 km in 50:00
Suppose you run 10 kilometres and the clock reads 50 minutes. Here is how the pace and speed fall out.
- 1 Convert the time to seconds. 50:00 = 50 × 60 = 3000 seconds.
- 2 Divide time by distance. pace = 3000 s ÷ 10 km = 300 seconds per kilometre.
- 3 Express pace as minutes:seconds. 300 s = 5 min 0 s, so the pace is 5:00 /km.
- 4 Find the equivalent speed. speed = 10 km ÷ (3000 ÷ 3600) h = 12 km/h, which is 12 ÷ 1.609 ≈ 7.46 mph.
- 5 Project a race time. Hold 5:00 /km over a marathon: 300 × 42.195 = 12 658.5 s ≈ 3:30:59.
Finish times at 5:00 /km
Predicted finish times if you hold a 5:00 per-kilometre pace (12 km/h) the whole way.
| Race | Distance | Finish time |
|---|---|---|
| 5K | 5 km | 25:00 |
| 10K | 10 km | 50:00 |
| Half marathon | 21.1 km | 1:45:30 |
| Marathon | 42.195 km | 3:30:59 |
Pace versus speed, and even splits
Pace and speed describe the same run from opposite directions. Runners usually think in pace because it maps cleanly onto distance markers — a 5:00 /km runner expects the watch to tick over every five minutes — while speed (km/h or mph) is handier for treadmills and cycling. To convert between units, remember one mile is 1.609 km: divide a min/km pace by 1.609 to get min/mile, and multiply the other way.
Race predictions above assume even splits — the same pace from start to finish. Real races drift: many runners go out too fast and slow in the back half (a positive split), while a controlled negative split — running the second half slightly faster — is a common strategy for a strong finish. Heat, hills, and fatigue all push your real pace above the flat-ground number, so treat these as best-case targets rather than guarantees.