Splits are your checkpoints: hitting them keeps you on target. This calculator gives the time for each split and handles the odd leftover piece at the end (like the final 0.195 km of a marathon).
How to use the Running Splits Calculator
- Total distance
- Custom distance
- I know my
- Total time – hours
- minutes
- seconds
- Pace – minutes
- seconds
- Pace unit
- Split distance
- Custom split distance
- Check split number
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Enter the total distance, your pace or total time, the split distance and a split number to check.
Inputs explained
| Field | What to enter |
|---|---|
| Total distance | Choose one: 100 m, 200 m, 400 m, 800 m … |
| Custom distance | Units: km, mi, m, yd |
| I know my | Choose one: Total time, Pace |
| Total time – hours | A number |
| minutes | A number |
| seconds | A number |
| Pace – minutes | A number |
| seconds | A number |
| Pace unit | Choose one: per km, per mile |
| Split distance | Choose one: 1 km, 1 mile, 400 m lap, 5 km … |
| Custom split distance | Units: km, mi, m, yd |
| Check split number | A number |
What each result means
- Number of full splits = floor([d]÷[S] + 1e-9)
- Time per split = [spm]×[S]
- Leftover distance = [d] – floor([d]÷[S] + 1e-9)×[S]
- Leftover time = [spm]×([d] – floor([d]÷[S] + 1e-9)×[S])
- Elapsed time at split n = [spm]×min([d], [Check split number]×[S])
- Remaining time after split n = [spm]×max(0, [d] – [Check split number]×[S])
- Total time = [spm]×[d]
Formula
Splits = distance ÷ split distance · Split time = pace × split distance · Elapsed at split n = n × split time
Worked example
Inputs — Total distance: Marathon; I know my: Total time; Total time – hours: 3; minutes: 30; seconds: 0; Split distance: 1 km; Check split number: 21.
Results — Number of full splits = 42; Time per split = 4:59; Leftover distance = 0.195 km; Leftover time = 0:58; Elapsed time at split n = 1:44:31; Remaining time after split n = 1:45:29; Total time = 3:30:00.
Key terms
- Split
- Time for one section of a race.
Frequently asked questions
What are negative splits?
Running the second half faster than the first.
What split distance should I use?
Kilometres or miles for road races; 400 m laps on the track.
Why is there a leftover?
Race distances rarely divide exactly by the split distance.
Should I adjust splits for hills?
Yes – aim for even effort rather than exactly even pace on hilly courses.