Plan
Race pace planner
Your goal
Metric0%
NegativeEvenPositive
Even split — same pace throughout.
Split Ladder
Marathon| Segment | Block | Split | Elapsed | Pace /km |
|---|---|---|---|---|
| 0km–5km | 5km | 24:53 | 24:53 | 4:59 |
| 5km–10km | 5km | 24:53 | 49:46 | 4:59 |
| 10km–15km | 5km | 24:53 | 1:14:39 | 4:59 |
| 15km–21.1km | 6.1km | 30:21 | 1:45:00 | 4:59 |
| 21.1km–30km | 8.9km | 44:18 | 2:29:18 | 4:59 |
| 30km–35km | 5km | 24:53 | 2:54:11 | 4:59 |
| 35km–40km | 5km | 24:53 | 3:19:04 | 4:59 |
| 40km–42.2km | 2.2km | 10:56 | 3:30:00 | 4:59 |
| Total | 42.2km | 3:30:00 | 42.2km | 4:59 |
Worked example
A 3:30:00 marathon target paces at 4:59/km, putting halfway at 1:45:00 and 30 km at 2:29:18. Sliding to a 1% negative split moves halfway out to 1:46:03 and asks for 4:56/km over the back half — the same finish, run the other way round.
Common questions
- What pace do I need for a sub-4 marathon?
- 5:41/km, or 9:09/mile, held for the full 42.2 km. Enter 4:00:00 above and the planner returns every checkpoint split, so you can check yourself against the course clocks rather than doing the arithmetic at 30 km.
- What pace is a 2:00 half marathon?
- 5:41/km, the same pace as a sub-4 marathon over half the distance. Set the distance to Half Marathon and the planner splits it at 5 km intervals plus the final 1.1 km.
- Should I run an even or a negative split?
- Negative, in almost every case. The fastest marathons are run with a slightly quicker second half, and going out hard is the most common way a goal is lost. The slider defaults to even; a 1 to 2 percent negative bias is a realistic plan for most runners.
- Why don't the splits match my watch exactly?
- Course distance is measured on the shortest legal line and almost nobody runs it. Most GPS watches read a marathon long by 200 to 400 metres, so your watch pace will look slightly faster than plan while your clock time stays on target. Race the course clocks, not the watch.
- Is this plan realistic for me?
- The planner allocates the goal you give it — it does not judge whether you can hold it. Run your recent race through the predictors first, then bring the projected time back here.