Marathon Pace Calculator — target time to pace, with split schedule

How it works

This is the running-pace calculation run backwards. Instead of measuring a run and reading off the pace, you set a goal — a race and a finish time — and it returns the pace you have to hold to get there. The distance is fixed by the race: 5 km, 10 km, the half-marathon's 21.0975 km, or the marathon's 42.195 km, both as defined by World Athletics. Pace is simply the target time divided by that distance.

The split schedule is the practical half of the page. If you hold an even pace, the time you should be through each checkpoint is just that fraction of your target — a quarter of the way at a quarter of the time, halfway at half. The halfway split is the number marathoners quote most: to run 4:00:00, you go through halfway at 2:00:00. Going through faster than that is "banking time" that usually gets paid back with interest in the final miles.

Worked example

A 4:00:00 marathon:

• Pace: 4:00:00 is 14,400 seconds; over 42.195 km that's 14,400 ÷ 42.195 = 341 seconds, or 5:41 per kilometre. Per mile it's 341 × 1.609344 ≈ 549 seconds, 9:09. As a speed, 42.195 ÷ 4 = 10.55 km/h.
• Splits: at even pace, quarter at 1:00:00, halfway at 2:00:00, three-quarter at 3:00:00, finish at 4:00:00.

Because the half-marathon is exactly half the marathon, a 2:00:00 half needs the identical 5:41/km — a useful check that a goal at one distance is consistent with another.

Frequently asked questions

How is race pace different from the running pace calculator?

The running-pace page takes a run you've done — a distance and a time — and tells you the pace. This page runs it the other way: you give a target finish time for a set race distance, and it returns the pace you'd need. Same arithmetic, opposite direction. Use running-pace to analyse a run; use this to plan one.

What is the halfway split and why does it matter?

It's the elapsed time you should reach the midpoint of the race at, running even pace — half your target. It matters because even or slightly negative splits (second half as fast or faster than the first) are how most runners achieve a goal time; going out far ahead of the halfway split is the classic way to fade. For a 4:00:00 marathon the halfway split is 2:00:00.

Should I actually run even splits?

Even pacing is the simplest plan and a good default, which is what the schedule here assumes. Real race tactics vary — some runners target a slight negative split, and hilly or hot courses call for uneven effort. Treat the schedule as the even-pace baseline to adjust from, not a rule.

Can I use this for any race, not just a marathon?

Yes — the race selector covers 5K, 10K, half-marathon and marathon. The page is titled for the marathon because that's the most-searched race pace, but the maths is identical for the shorter distances; only the distance the time is divided by changes.

Why does a slower goal time give a bigger pace number?

Because pace is time per distance: more time over the same distance means more time per kilometre. A 5:00:00 marathon is 5:00:00 ÷ 42.195 = 7:07 per kilometre, slower — a larger number — than a 4:00:00's 5:41. It can feel back-to-front that a bigger goal time gives a bigger pace, but both are measuring the same thing: the seconds each kilometre takes.

Does this account for hills, heat or fatigue?

No. It computes the mathematically even pace for your target and nothing else. Courses with significant climb, hot or humid conditions, and the natural slowing of a long race all mean your actual splits will vary around this schedule. It is a pacing target, not a prediction of how the race will unfold.

How precise are the splits?

The arithmetic is exact for the target and distance. On the ground, precision is limited by your watch and by course markings, which can disagree with GPS by a few percent — most marathoners run slightly further than the official distance because they don't hold the shortest line, so plan a small margin.