Tools Pace Calculator
Pace, time, splits — solved
Pick a distance, give a target time to get the pace it demands — or give a pace to get your finish time — and read the full splits table in kilometres or miles. Running pace is just time divided by distance; the discipline is holding it, and that starts with knowing the number.
h:mm:ss or mm:ss. You can also type 4h or 3h45m. Read as 50:00.
Pace /km
5:00
Pace /mi
8:03
Finish time
50:00
Distance
10km
A goal like “sub-4” means finishing under 4:00:00, so pacing to exactly 4:00:00 leaves nothing for a long tangent or a slow mile. Choose your own margin — RunV does not decide it for you, and zero is a valid answer.
This is arithmetic: the two halves are redistributed so they still sum to your finish time. It is not a course-specific strategy, and it does not know where the hills are.
Splits — every kilometre
10 checkpoints
| At | Elapsed | Segment | Pace |
|---|---|---|---|
| 1 km | 5:00 | 5:00 | 5:00/km |
| 2 km | 10:00 | 5:00 | 5:00/km |
| 3 km | 15:00 | 5:00 | 5:00/km |
| 4 km | 20:00 | 5:00 | 5:00/km |
| 5 km · halfway | 25:00 | 5:00 | 5:00/km |
| 6 km | 30:00 | 5:00 | 5:00/km |
| 7 km | 35:00 | 5:00 | 5:00/km |
| 8 km | 40:00 | 5:00 | 5:00/km |
| 9 km | 45:00 | 5:00 | 5:00/km |
| 10 km · finish | 50:00 | 5:00 | 5:00/km |
Every checkpoint is listed — nothing is truncated. Your watch will read slightly long against these: GPS records the line you actually ran, while a race is measured along the shortest legal route.
How this works
Pace is time divided by distance. Everything on this page comes from that one operation, applied to numbers held internally in seconds and metres and rounded only when displayed — so a split table always adds up to the finish time you asked for.
Standard distances are used exactly: the marathon is 42.195 km and the half is 21.0975 km, not 42.2 and 21.1. Over a marathon that difference is about eighteen seconds at four-hour pace, which is enough to matter to someone chasing a round number.
The pacing-shape control redistributes time between the two halves and nothing else. Each half is run at its own constant pace, so the halves always sum to the total. It is arithmetic about a clock, not advice about a course — it does not know where the hills are.
A worked example
A 50:00 target for 10 km. 3,000 seconds divided by 10,000 metres is 0.3 seconds per metre, which is 5:00 per kilometre, 8:03 per mile, or 12.00 km/h.
A four-hour marathon is 14,400 seconds over 42,195 m: 5:41 per kilometre (9:09 per mile). Note that 5:41 × 42.195 is about 4:00:03 — the pace is rounded for display, the splits are not, and the finish row still reads exactly 4:00:00.
What this cannot tell you
This is arithmetic, not a prediction. It says what pace a time requires; it says nothing about whether you can hold it. For that, start from a recent race with the race predictor.
Splits assume a constant pace within each half and a course measured to its official distance. Real races have hills, wind, congestion at the start and tangents you will not run perfectly. Treat the table as a target to steer by, not a schedule to obey to the second.
Sources
Standard road race distances (World Athletics course measurement)
Marathon 42.195 km, half marathon 21.0975 km — used exactly, not rounded.
Pace = time ÷ distance
Arithmetic, not a model. No assumptions beyond the two numbers you enter.
Method version 2.0 · sources and method last reviewed by a person on 2026-09-08.
That review date is not a deploy date. It changes when someone checks the method, and at no other time.
Asked often
- How do I work out my running pace?
- Divide your finish time by the distance: a 50:00 10K is 5:00 per kilometre (about 8:03 per mile). This calculator does the division — and the reverse: give it a pace and distance and it returns your finish time with every split.
- What pace do I need for common goals?
- A 4-hour marathon needs 5:41/km, a 2-hour half needs 5:41/km too, a 50-minute 10K needs 5:00/km, and a 25-minute 5K needs 5:00/km. Same paces, very different efforts — distance is the multiplier.
- Why does my watch say I ran further than the race distance?
- Because GPS records the line you actually ran, while a race is measured along the shortest legal route. Running wide on bends over a marathon can easily add 200-400 m, which is a minute or more of clock time. Pace from your watch will therefore read slightly quicker than the pace the finish clock implies — both numbers are right, they are measuring different distances.
- How do I enter four hours without it being read as four minutes?
- Type 4:00:00, or 4h. A bare "4:00" is minutes and seconds, which is what someone entering a pace means. If you arrive from an older link that used the ambiguous form, the calculator resolves it against the distance — four minutes for a marathon would be a physically impossible pace — and tells you how it read it.
- Should I pace in minutes per kilometre or per mile?
- Whichever your watch and race markers use — the calculator shows both. UK and European races mark kilometres; US races mark miles. What matters is knowing your target in the unit you'll actually see on course.
Knowing the pace is easy. Holding it is coached.
RunV's live audio coaching keeps you on these numbers mid-run — and its plans are built from the same arithmetic. Browse goal-time training plans to see the structure behind the splits.
