Negative Split Marathon Pacing Guide

Plan a negative-split marathon with a worked 4-hour example. Learn first-half targets, second-half pacing, and when hills or heat make even effort better.

A negative split means running the second half faster than the first. For a marathon, aim for a small, realistic difference rather than a slow first half followed by a desperate catch-up. The calculator below estimates training paces; use the worked example here to plan race splits.

For a 4:00 marathon with a two-minute difference between halves, run the first half in 2:01 and the second in 1:59.
Those half-marathon splits average about 5:44/km then 5:38/km (9:14/mile then 9:05/mile), rounded to the nearest second.
Calculate the first half as (goal time + split difference) / 2 and the second as (goal time - split difference) / 2.
On a hilly course or in rising heat, even effort can be more sensible than forcing a faster second half. Keep fueling consistent from early in the race.

How to plan a small negative split

Set realistic half-marathon checkpoints without banking time early.

Choose a realistic finish time: Base it on recent races and marathon-specific training, not only an aspirational goal.
Divide the halves: Add the desired difference to the goal time and divide by two for the first half; subtract it and divide by two for the second.
Adjust for the course: Check the elevation profile and conditions, then prioritize sustainable effort and early fueling.

Frequently asked questions

What is a negative split in a marathon?

It means your second 21.0975km is faster than your first. For example, 2:01 followed by 1:59 gives a 4:00 finish and a two-minute negative split.

Does a two-minute negative split mean starting two minutes slower than halfway?

No. The difference is between the two halves. For a 4:00 goal, shift one minute from the second half to the first: 2:01 plus 1:59, not 2:02 plus 1:58.

Is a negative split always the best marathon strategy?

No. Even pacing can also work well, and course elevation, wind, heat, fitness, and fueling change the best approach. Avoid chasing a planned split when the effort is clearly too high.

Training pace reference

Training paces by recent 5K time (min/km)
5K time	VDOT	Easy	Marathon	Threshold	Interval	Rep
15:00	69.6	3:45–4:30	3:23–3:42	3:15	2:56	2:32
17:30	58.2	4:20–5:12	3:54–4:17	3:46	3:23	2:56
20:00	49.8	4:54–5:53	4:26–4:51	4:16	3:51	3:19
22:30	43.4	5:29–6:34	4:57–5:25	4:46	4:18	3:43
25:00	38.3	6:03–7:14	5:28–5:59	5:16	4:45	4:06
27:30	34.2	6:37–7:53	5:59–6:33	5:46	5:13	4:30
30:00	30.8	7:11–8:32	6:30–7:06	6:16	5:40	4:54
32:30	28.0	7:44–9:10	7:01–7:39	6:46	6:07	5:17
35:00	25.6	8:17–9:48	7:31–8:12	7:15	6:34	5:41

More pacing guides

Method and sources

The numbers on this page are computed with the same code as the TrainPace calculators, from these published methods. They are training guidance, not medical advice.

Daniels, J. Daniels' Running Formula. Human Kinetics — VDOT, training zones, and equivalent race times.
Daniels, J. & Gilbert, J. (1979). Oxygen Power: Performance Tables for Distance Runners — the oxygen-cost and %VO2max equations behind VDOT.

Other TrainPace tools

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