Plain Words Running data, in plain words.

Racing smarter

What pace is a 4:15 marathon?

4:15:00 for the marathon is 6:03/km (9:44/mi), held the whole way. Halfway on even pace is 2:07:30. Most watches measure the course long, so the pace you actually need on the screen is nearer 5:57/km.

The numbers on this page, in one place.
WhatNumberThe qualifier
Pace needed6:03/km (9:44/mi)even, start to finish
Halfway (even)2:07:302:10:03 on a 2% negative split
Watch pace at 1.5% overage5:57/km (9:35/mi)what the screen has to show
Distance42.195 km (26.22 mi)the measured course, not the watch

What pace is a 4:15 marathon?

4:15:00 over 42.195 km (26.22 mi) is 6:03/km (9:44/mi), held from the first step to the last. There is no rounding slack in that number: run the first kilometre at 6:13/km and you have already spent ten seconds you will not get back cheaply.

4:15 is often a sub-four attempt that has been sensibly revised, and it is usually the smarter race. At 6:02/km (9:43/mi) the effort is genuinely conversational for the first two hours for most people who have done the long runs. That changes the tactical question. When the pace is comfortable early, the risk is not blowing up, it is drifting. Runners at this target commonly run the first half at 4:05 pace without noticing, because it feels the same, and then pay for it at 30 km. Check your watch at 5 km and again at 10 km, and if you are more than 40 seconds ahead of schedule, slow down. Being on pace at halfway is worth more than any cushion.

What the splits look like

KilometreSplitElapsed
16:036:03
56:0330:13
106:031:00:26
156:031:30:39
206:032:00:52
256:032:31:05
306:033:01:18
356:033:31:31
406:034:01:44
42.1951:114:15:00

And in miles, for a course measured that way:

MileSplitElapsed
19:449:44
39:4429:11
69:4458:21
99:441:27:32
129:441:56:43
159:442:25:53
189:442:55:04
219:443:24:15
249:443:53:25
26.222:084:15:00

Where should I be at halfway?

Even pace puts you through halfway at 2:07:30. Most people who finish this time went through slightly slower than that, not faster — a 2% negative split means halfway at 2:10:03 and a second half of 2:04:57.

The decision rule for race day: if you reach halfway more than 2:33 ahead of 2:07:30, you are not ahead of schedule, you are borrowing. Ease back to 6:03/km (9:44/mi) and hold it.

What if my watch measures the course long?

Almost every watch does. A marathon that reads 1.5% long on your wrist means you have to run 5:57/km by the watch to finish in 4:15:00 by the clock. That is the pace to put on the screen, and it is why pacing off a watch's average-pace field alone tends to leave people a minute or two short.

Questions runners actually ask

Is a 4:15 marathon a good time?
Good is a comparison, and it depends who with. Whether it is achievable for you is the answerable question: it comes down to a recent race, your weekly volume and your longest run. The race predictor puts numbers on all three.
Should I run even splits or negative splits?
Even, planned; slightly negative, executed. Going through halfway 1-2% slower than even pace costs almost nothing if you are strong at the end, and saves the race if you are not.

Sources

Changelog

  • — First published.