Pace is time divided by distance — speed is the flip of it
Pace tells you the time to cover one kilometer or one mile; speed tells you the distance covered in an hour. They describe the same run from two angles. Runners plan in pace because it maps straight onto a race target — a finish time is just pace multiplied by the race distance.
Pace to speed at a glance
| Pace (min/km) | Speed (km/h) | Pace (min/mile) | Feels like |
|---|---|---|---|
| 4:00 | 15.0 | 6:26 | Hard 5K |
| 5:00 | 12.0 | 8:03 | 10K effort |
| 6:00 | 10.0 | 9:39 | Easy run |
| 7:00 | 8.6 | 11:16 | Long, slow run |
| 8:00 | 7.5 | 12:52 | Recovery jog |
A mile is 1.609 km, so a min/mile pace is always a larger number than the same effort in min/km.
Finish times at a steady pace
Finish time equals pace times distance, assuming you hold that pace the whole way. The four standard race distances:
| Pace (min/km) | 5K | 10K | Half (21.1 km) | Marathon (42.2 km) |
|---|---|---|---|---|
| 5:00 | 25:00 | 50:00 | 1:45:30 | 3:30:59 |
| 5:30 | 27:30 | 55:00 | 1:56:04 | 3:52:04 |
| 6:00 | 30:00 | 1:00:00 | 2:06:35 | 4:13:10 |
| 7:00 | 35:00 | 1:10:00 | 2:27:41 | 4:55:22 |
Real races rarely hold one pace end to end. Most amateurs slow in the second half (a positive split); pacing evenly, or slightly faster late, gets you a better time.
The distinction that trips people up
- Pace and speed are inverses. Lower pace is faster; higher speed is faster. 5:00 min/km and 12 km/h are the same run.
- min/km is not min/mile. The same effort reads as a bigger number per mile because a mile is longer. Check which unit a plan or watch is using before comparing.
- Longer races need a slower pace. You cannot stretch 5K pace over a marathon; the sustainable pace drops as the distance grows, which is why predictions add a slow-down factor.
Common questions
How do I calculate my running pace?
Divide your total time by the distance. Run 10 km in 50 minutes and your pace is 5 minutes per kilometer. To get speed instead, divide 60 by the pace: 60 divided by 5 is 12 km/h.
How fast is a 6 minute per kilometer pace?
That is 10 km/h. In one hour at 6 minutes per kilometer you cover exactly 10 kilometers.
Can I predict my marathon time from a shorter race?
Only roughly. Holding a 10K pace across a full marathon almost never happens, so add about 15 to 20 percent to the pace. A 5:00 per km 10K points to roughly 5:54 per km over 42.2 km, about 4 hours 10 minutes.
