# Running pace calculator: average speed, pace per km and splits

Source: https://justzon.com/blog/calculateur-allure-running
Author: ZON team (hybrid coaching)
Published: 2026-06-16 · Updated: 2026-06-16

Enter your distance and time, and get instantly your average speed (km/h), your pace (min/km) and every split, kilometre by kilometre and at the key distances (5 km, 10 km, half, marathon). Mastering pace is the number-one lever to progress and manage effort in running.

## Pace vs speed

- **Speed (km/h)** = distance you'd cover in one hour at that rhythm. Unit of treadmills and bikes.
- **Pace (min/km)** = time you need to cover one kilometre. Reference unit for runners and GPS watches because it translates directly into splits.
- Relation: **speed (km/h) = 60 ÷ pace (min/km)**. 5:00/km = 12 km/h. 6:00/km = 10 km/h.

## How to compute pace and speed

- Pace (min/km) = total time ÷ distance. 10 km in 50 min: 50 ÷ 10 = **5:00/km**.
- Speed (km/h) = distance ÷ time (in hours). 10 km in 0.833 h (50 min): 10 ÷ 0.833 = **12 km/h**.
- Always convert total time to seconds first (hours × 3600 + minutes × 60 + seconds).

## Examples by distance

| Race | Time | Pace | Average speed |
|---|---|---|---|
| 5 km | 30:00 | 6:00 /km | 10 km/h |
| 10 km | 50:00 | 5:00 /km | 12 km/h |
| Half marathon (21.0975 km) | 2:00:00 | 5:41 /km | 10.55 km/h |
| Marathon (42.195 km) | 4:00:00 | 5:41 /km | 10.55 km/h |

A 2-hour half and a 4-hour marathon are run at the same pace (5:41/km). Marathon pace is almost always slower than 10K pace for the same runner.

## Reference pace table

| Pace | Speed | 10 km | Half | Marathon |
|---|---|---|---|---|
| 4:00 /km | 15.0 km/h | 40:00 | 1:24:23 | 2:48:47 |
| 4:30 /km | 13.3 km/h | 45:00 | 1:34:56 | 3:09:53 |
| 5:00 /km | 12.0 km/h | 50:00 | 1:45:29 | 3:30:59 |
| 5:30 /km | 10.9 km/h | 55:00 | 1:56:02 | 3:52:04 |
| 6:00 /km | 10.0 km/h | 1:00:00 | 2:06:35 | 4:13:10 |
| 6:30 /km | 9.2 km/h | 1:05:00 | 2:17:08 | 4:34:16 |
| 7:00 /km | 8.6 km/h | 1:10:00 | 2:27:41 | 4:55:22 |

## Why splits matter

Splits are cumulative times at each marker. They turn an abstract goal ("finish in 50 minutes") into concrete cues ("hit 5 km at 25:00").

- **Hold your rhythm.** Watch vs split plan tells you in real time if you're too fast or too slow.
- **Avoid the too-fast start.** Runner mistake #1.
- **Manage energy.** On a half or marathon, leaving 10 s/km too fast on the first half is paid cash on the second.

## Pacing tips by distance

- **5 and 10 km:** high pace, no sprint off the line. Aim slightly below target pace on km 1, then stabilize. Negative split is often the best strategy.
- **Half marathon:** regularity wins. Most PRs are run at near-constant pace.
- **Marathon:** pacing is everything. The famous 30 km wall is often a pacing wall: starting too fast empties the tank too early.

## FAQ

**How do I calculate my average running speed?** Divide distance (km) by time (hours). 10 km in 0.75 h = 13.3 km/h.

**Pace vs speed?** Pace = time per km (min/km). Speed = distance per hour (km/h). Conversion: speed = 60 ÷ pace.

**Can I use it for a marathon?** Yes, all distances. Enter 42.195 km and your target time.

**What's a good split?** One that lets you hold target pace all the way. A slightly conservative first half beats a too-fast start.

**Is the projected pace guaranteed?** No: constant pace is assumed. Terrain, elevation, heat and fatigue shift the real rhythm.

## Related

- Hyrox Pace Calculator 2026, split-by-split race strategy: https://justzon.com/blog/hyrox-pace-calculator
- How to combine strength and running, a coach's framework: https://justzon.com/blog/how-to-combine-strength-and-running