Running Pace Calculator
Enter any two of distance, finish time and pace, and this calculator works out the third — with equivalent kilometre and mile pace, average speed, and even-pace splits.
8:03 /mile
| Distance | Cumulative time |
|---|---|
| 1 km | 5:00 |
| 2 km | 10:00 |
| 3 km | 15:00 |
| 4 km | 20:00 |
| 5 km | 25:00 |
| Step | Value |
|---|---|
| Distance entered | 5.00 km |
| Finish time entered | 25:00 |
| Time in seconds | 1,500 seconds |
| Pace calculation | 1,500 ÷ 5.00 |
| Pace in seconds | 300 sec/km |
| Your running pace | 5:00 /km |
| Equivalent pace | 8:03 /mile |
| Average speed | 12.0 km/h |
This calculator assumes an even pace throughout the run. Actual times and splits can be affected by terrain, elevation, weather, stops, fatigue, fuelling and pacing strategy.
What this calculator does
Enter any two of distance, finish time and pace to calculate the third. The calculator also shows the equivalent pace per kilometre and per mile, your average speed in km/h and mph, and an even-pace split table for the whole run.
It works in kilometres or miles without changing the underlying maths: every calculation runs in seconds and kilometres internally, and units are converted only when a value is read from an input or shown in a result.
How to use this calculator
- Choose what to calculate — Pace, Finish time or Distance. Only the two inputs that mode needs are shown.
- Enter the distance in kilometres or miles, or tap a quick-distance preset (1 km, 1 mile, 5K, 10K, half marathon or marathon).
- Enter the finish time as hours, minutes and seconds, or the target pace as minutes and seconds.
- Read the result: your pace, finish time or distance, plus equivalent km and mile pace, average speed, and the even-pace split table.
Switching the distance unit converts the value you have already entered rather than clearing it.
How running pace is calculated
All three modes are the same relationship rearranged:
- Finish time = Distance × Pace
- Distance = Time ÷ Pace
- Speed = Distance ÷ Time, or 3,600 ÷ pace in seconds per kilometre
Time is handled in seconds and distance in kilometres, so pace is seconds per kilometre and speed is kilometres per hour. A per-mile pace is the per-kilometre pace multiplied by 1.609344; a mile distance is converted to kilometres the same way.
- Displayed pace and time are rounded to the nearest second.
- Distances are shown to two decimal places, speed to one.
- No intermediate value is rounded before the final figure is formatted.
Worked example — pace. 5 km in 25:00 is 1,500 seconds ÷ 5 km = 300 seconds per km = 5:00 / km. Multiplied by 1.609344 that is about 483 seconds, or 8:03 / mile. Average speed is 3,600 ÷ 300 = 12.0 km/h (7.5 mph).
Worked example — finish time. 10 km at 5:30 / km is 330 seconds per km, so 10 × 330 = 3,300 seconds = 55:00.
Worked example — distance. 45:00 at 6:00 / km is 2,700 seconds ÷ 360 seconds per km = 7.5 km, or 7.50 km (4.66 miles).
Common running distances
| Distance | Kilometres | Miles |
|---|---|---|
| 1 km | 1 | 0.62 |
| 1 mile | 1.6093 | 1.00 |
| 5K | 5 | 3.11 |
| 10K | 10 | 6.21 |
| Half marathon | 21.0975 | 13.11 |
| Marathon | 42.195 | 26.22 |
The marathon is exactly 42.195 km and the half marathon exactly 21.0975 km, as set by World Athletics. A 5K is 5 km and a 10K is 10 km.
What the even-pace split table shows
The split table lists the cumulative elapsed time at each whole kilometre or mile, assuming you run the whole distance at one steady pace. It always includes a final row for the full distance, even when that is a partial split, and it is limited to the first 50 full splits plus the finish so a very long run stays readable.
Real runs are rarely perfectly even. The table is a pacing reference, not a prediction — it does not model negative or positive splits, hills, wind, aid-station stops, terrain or fuelling.
Limitations
This calculator assumes a constant, even pace. It does not account for terrain, elevation, weather, stops, fatigue, fuelling, race-day conditions or pacing strategy, and it makes no training, performance or medical claims.
For the calories side of training, the maintenance calories calculator estimates how much energy you use in a day, and the weight loss calorie calculator turns that into a daily target for weight loss.