Goal time
Sub-3-hour marathon pace
Three hours is the line that separates serious amateur marathon running from everything else, and it is the least forgiving target on this site. There is very nearly no margin in it.
The pace this target demands
- Finish time
- 3:00:00
- Per mile
- 6:52
- Per kilometer
- 4:16
- Speed
- 8.7 mph
The time to actually aim at
3:00:00 is a ceiling, not a target. Plan for 2:59:00 instead and you get 6:50 per mile, which buys back the seconds a long tangent, a crowded water station or a slow first quarter-mile will cost you.
The paces on this page are shown to the nearest second, which is how a watch shows them. Typing a rounded pace back into a calculator will not return the exact target time, and no amount of decimal places fixes that on a real course.
The pace is under seven minutes a mile for the entire distance, which is not a pace most people can carry a conversation at, and that changes how the plan works. At sub-4 a bad patch costs you minutes you might have. Here it costs you the target. The margin table further down is the one to spend time with.
Splits every 1 mi
An even effort from start to finish. Cumulative time is the clock reading as you pass each marker.
Every one of these mile splits has to be genuinely on pace. Losing ten seconds twice, on two hills, is the whole buffer gone with nothing bought back.
Scroll the table sideways on a narrow screen.
Splits every 1 mi
| Split | Distance | Split time | Cumulative | Pace |
|---|---|---|---|---|
| 1 | 1.00 | 6:52 | 6:52 | 6:52 |
| 2 | 2.00 | 6:52 | 13:44 | 6:52 |
| 3 | 3.00 | 6:52 | 20:36 | 6:52 |
| 4 | 4.00 | 6:52 | 27:28 | 6:52 |
| 5 | 5.00 | 6:52 | 34:20 | 6:52 |
| 6 | 6.00 | 6:52 | 41:12 | 6:52 |
| 7 | 7.00 | 6:52 | 48:03 | 6:52 |
| 8 | 8.00 | 6:52 | 54:55 | 6:52 |
| 9 | 9.00 | 6:52 | 1:01:47 | 6:52 |
| 10 | 10.00 | 6:52 | 1:08:39 | 6:52 |
| 11 | 11.00 | 6:52 | 1:15:31 | 6:52 |
| 12 | 12.00 | 6:52 | 1:22:23 | 6:52 |
| 13 | 13.00 | 6:52 | 1:29:15 | 6:52 |
| 14 | 14.00 | 6:52 | 1:36:07 | 6:52 |
| 15 | 15.00 | 6:52 | 1:42:59 | 6:52 |
| 16 | 16.00 | 6:52 | 1:49:51 | 6:52 |
| 17 | 17.00 | 6:52 | 1:56:43 | 6:52 |
| 18 | 18.00 | 6:52 | 2:03:35 | 6:52 |
| 19 | 19.00 | 6:52 | 2:10:26 | 6:52 |
| 20 | 20.00 | 6:52 | 2:17:18 | 6:52 |
| 21 | 21.00 | 6:52 | 2:24:10 | 6:52 |
| 22 | 22.00 | 6:52 | 2:31:02 | 6:52 |
| 23 | 23.00 | 6:52 | 2:37:54 | 6:52 |
| 24 | 24.00 | 6:52 | 2:44:46 | 6:52 |
| 25 | 25.00 | 6:52 | 2:51:38 | 6:52 |
| 26 | 26.00 | 6:52 | 2:58:30 | 6:52 |
| 27 | 26.22 | 1:30 | 3:00:00 | 6:52 |
Splits every 1 km
| Split | Distance | Split time | Cumulative | Pace |
|---|---|---|---|---|
| 1 | 1.00 | 4:16 | 4:16 | 4:16 |
| 2 | 2.00 | 4:16 | 8:32 | 4:16 |
| 3 | 3.00 | 4:16 | 12:48 | 4:16 |
| 4 | 4.00 | 4:16 | 17:04 | 4:16 |
| 5 | 5.00 | 4:16 | 21:20 | 4:16 |
| 6 | 6.00 | 4:16 | 25:36 | 4:16 |
| 7 | 7.00 | 4:16 | 29:52 | 4:16 |
| 8 | 8.00 | 4:16 | 34:08 | 4:16 |
| 9 | 9.00 | 4:16 | 38:24 | 4:16 |
| 10 | 10.00 | 4:16 | 42:40 | 4:16 |
| 11 | 11.00 | 4:16 | 46:55 | 4:16 |
| 12 | 12.00 | 4:16 | 51:11 | 4:16 |
| 13 | 13.00 | 4:16 | 55:27 | 4:16 |
| 14 | 14.00 | 4:16 | 59:43 | 4:16 |
| 15 | 15.00 | 4:16 | 1:03:59 | 4:16 |
| 16 | 16.00 | 4:16 | 1:08:15 | 4:16 |
| 17 | 17.00 | 4:16 | 1:12:31 | 4:16 |
| 18 | 18.00 | 4:16 | 1:16:47 | 4:16 |
| 19 | 19.00 | 4:16 | 1:21:03 | 4:16 |
| 20 | 20.00 | 4:16 | 1:25:19 | 4:16 |
| 21 | 21.00 | 4:16 | 1:29:35 | 4:16 |
| 22 | 22.00 | 4:16 | 1:33:51 | 4:16 |
| 23 | 23.00 | 4:16 | 1:38:07 | 4:16 |
| 24 | 24.00 | 4:16 | 1:42:23 | 4:16 |
| 25 | 25.00 | 4:16 | 1:46:39 | 4:16 |
| 26 | 26.00 | 4:16 | 1:50:55 | 4:16 |
| 27 | 27.00 | 4:16 | 1:55:11 | 4:16 |
| 28 | 28.00 | 4:16 | 1:59:27 | 4:16 |
| 29 | 29.00 | 4:16 | 2:03:43 | 4:16 |
| 30 | 30.00 | 4:16 | 2:07:59 | 4:16 |
| 31 | 31.00 | 4:16 | 2:12:15 | 4:16 |
| 32 | 32.00 | 4:16 | 2:16:31 | 4:16 |
| 33 | 33.00 | 4:16 | 2:20:46 | 4:16 |
| 34 | 34.00 | 4:16 | 2:25:02 | 4:16 |
| 35 | 35.00 | 4:16 | 2:29:18 | 4:16 |
| 36 | 36.00 | 4:16 | 2:33:34 | 4:16 |
| 37 | 37.00 | 4:16 | 2:37:50 | 4:16 |
| 38 | 38.00 | 4:16 | 2:42:06 | 4:16 |
| 39 | 39.00 | 4:16 | 2:46:22 | 4:16 |
| 40 | 40.00 | 4:16 | 2:50:38 | 4:16 |
| 41 | 41.00 | 4:16 | 2:54:54 | 4:16 |
| 42 | 42.00 | 4:16 | 2:59:10 | 4:16 |
| 43 | 42.20 | 0:50 | 3:00:00 | 4:16 |
Three ways to spend the same time
The finish time is identical in all three. What changes is where the effort goes, and how the opening miles feel.
Scroll the table sideways on a narrow screen.
| Strategy | Opens at | Closes at | First half | Second half | Second half vs first |
|---|---|---|---|---|---|
| Even splits | 6:52 | 6:52 | 1:30:00 | 1:30:00 | Level |
| Negative splits | 7:00 | 6:43 | 1:30:54 | 1:29:06 | 1:49 faster |
| Positive splits | 6:44 | 7:00 | 1:29:06 | 1:30:54 | 1:49 slower |
Even splits
The same pace for every split. It is the plan that needs the least judgment and the one every other plan is measured against, and for a first attempt at a barrier it is usually the right answer.
Negative splits
Set here at 2 percent, which means the opening pace is 2 percent slower than even and the closing pace is 2 percent faster — a spread of 4 percent from the first split to the last. On the clock that is 7:00 out of the gate and 6:43 coming home. It costs discipline early and gives back a second half 1:49 quicker.
Positive splits
The mirror image, and the one that happens by accident more often than by choice. The same 4 percent spread, run the other way round: 6:44 early, 7:00 late. It is a real plan for a course that climbs at the end, and a warning sign everywhere else.
The percentage is the swing at each end, not the difference between the halves. Doubling it gives the spread from the first split to the last.
A three-hour marathon run positively almost always ends up as a 3:05. The negative-split row is not an aspiration here, it is the standard advice for a reason.
Clock time at every marker
An even effort, at the points a race actually marks. Worth writing on a wristband.
| Point | Elapsed | Remaining |
|---|---|---|
| 5 km | 21:20 | 2:38:40 |
| 10 km | 42:40 | 2:17:20 |
| 15 km | 1:03:59 | 1:56:01 |
| 20 km | 1:25:19 | 1:34:41 |
| Halfway | 1:30:00 | 1:30:00 |
| 25 km | 1:46:39 | 1:13:21 |
| 30 km | 2:07:59 | 52:01 |
| 20 mi | 2:17:18 | 42:42 |
| 35 km | 2:29:18 | 30:42 |
| 40 km | 2:50:38 | 9:22 |
| Finish | 3:00:00 | 0:00 |
What being off pace costs
Every row starts from the exact required pace and shifts it. This is the table to look at when the first mile comes up quick.
Per mile
| Off pace by | Pace | Finish time | Vs target |
|---|---|---|---|
| 15 s faster | 6:37 | 2:53:27 | 6:33 inside |
| 10 s faster | 6:42 | 2:55:38 | 4:22 inside |
| 5 s faster | 6:47 | 2:57:49 | 2:11 inside |
| Exactly on pace | 6:52 | 3:00:00 | On the line |
| 5 s slower | 6:57 | 3:02:11 | 2:11 over |
| 10 s slower | 7:02 | 3:04:22 | 4:22 over |
| 15 s slower | 7:07 | 3:06:33 | 6:33 over |
Per kilometer
| Off pace by | Pace | Finish time | Vs target |
|---|---|---|---|
| 15 s faster | 4:01 | 2:49:27 | 10:33 inside |
| 10 s faster | 4:06 | 2:52:58 | 7:02 inside |
| 5 s faster | 4:11 | 2:56:29 | 3:31 inside |
| Exactly on pace | 4:16 | 3:00:00 | On the line |
| 5 s slower | 4:21 | 3:03:31 | 3:31 over |
| 10 s slower | 4:26 | 3:07:02 | 7:02 over |
| 15 s slower | 4:31 | 3:10:33 | 10:33 over |
The middle row is the definition of the target rather than a way to hit it. Finishing at exactly 3:00:00 does not beat 3:00:00, which is the whole reason the aim-for time above exists.
Look at how little the plus-five-seconds row moves the finish, and then at how far past three hours it lands. That gap is the entire problem with this target.
The targets either side
Every other pace for this distance
The full lookup table for the Marathon, from a pace almost nobody holds down to a comfortable one, with finish times for all of them.
A distance that is not on this list?
The web calculator takes any distance, any time and any pace, and works out the rest as you type. Nothing to install, nothing to sign up for.
The app
Take the numbers to the start line
Simple Pace Calculator is a free app for iPhone & iPad. Distance, time, pace and speed stay in sync while you edit any one of them, and a lock shows which value is being held fixed. All calculations work offline.
$2.99 (US), one-time unlocks two extra tools, once, with no subscription: Splits, for even, negative or positive pacing at any interval, and ETA, for working out when a runner reaches your spot on the course.
For this distance the app offers splits every 1 km, 1 mi, 5 km, 5 mi, 1/2, 1/4, plus a custom interval of your own.
Everything on this page stays free on the web, whether or not you ever install anything.
