Sub-3:45 Marathon Pace
The quiet middle of the field, where pacing discipline pays the largest dividend.
A 3:45:00 marathon needs 5:20 per kilometre, which is 8:35 per mile, 11.3 kph or 7.0 mph. Held evenly across the full 42.195 km that puts you through halfway in 1:52:30 and on one 400 m lap every 2:08. The tables below give every kilometre split, every mile split and the checkpoint time at each marker.
| Measure | Value |
|---|---|
| Goal finish time | 3:45:00 |
| Pace per kilometre | 5:20 /km |
| Pace per mile | 8:35 /mi |
| Average speed | 11.3 kph (7.0 mph) |
| One 400 m lap | 2:08 |
| Even-split halfway | 1:52:30 |
3:45 rarely gets the attention that 3:30 and 4:00 attract, which is a little unfair, because it is a genuinely useful target for a runner who has finished a marathon before and wants a measurably better one. The pace is a step up from a first-marathon effort without demanding the precision of a sub-3:30 attempt.
This is the range where the second half of the race is decided almost entirely by how the first hour was run. The fade table below turns that into concrete finish times: a second half run five percent slower than the first is a very ordinary outcome, and it is worth seeing what that does to the clock before race day rather than after.
The mile table is worth a look even if you train in kilometres. Many marathons mark both, and a mile marker arriving between two kilometre markers gives you an extra chance to check your pacing without waiting another kilometre for confirmation. Both tables on this page are generated from the same goal time, so they agree exactly, and the last row of each lands on the goal rather than near it.
Checkpoint times for a 3:45:00 marathon
At 3:45 the useful checkpoints are the early ones. If 10 km is on the figure below rather than ahead of it, the rest of the plan is mostly patience.
| Marker | Elapsed | Remaining | Distance left (km) |
|---|---|---|---|
| 5 km | 26:40 | 3:18:20 | 37.195 |
| 10 km | 53:19 | 2:51:41 | 32.195 |
| 15 km | 1:19:59 | 2:25:01 | 27.195 |
| 20 km | 1:46:39 | 1:58:21 | 22.195 |
| Halfway (21.0975 km) | 1:52:30 | 1:52:30 | 21.098 |
| 25 km | 2:13:19 | 1:31:41 | 17.195 |
| 30 km | 2:39:58 | 1:05:02 | 12.195 |
| 35 km | 3:06:38 | 38:22 | 7.195 |
| 40 km | 3:33:18 | 11:42 | 2.195 |
| Finish (42.195 km) | 3:45:00 | 0:00 | 0 |
What a fade costs
This is the range where a five percent second half is the single most common outcome, so it is worth knowing that number before race day rather than reading it off the results sheet afterwards.
| Second half | First half | Second half time | Finish | Lost |
|---|---|---|---|---|
| Even | 1:52:30 | 1:52:30 | 3:45:00 | on goal |
| 2% slower | 1:52:30 | 1:54:45 | 3:47:15 | +2:15 |
| 5% slower | 1:52:30 | 1:58:08 | 3:50:38 | +5:38 |
| 10% slower | 1:52:30 | 2:03:45 | 3:56:15 | +11:15 |
Every kilometre split for a 3:45:00 marathon
All 43 rows, ending on the final 195 metres so the last elapsed time is exactly 3:45:00 rather than close to it.
| Marker | Segment time | Elapsed |
|---|---|---|
| 1 km | 5:20 | 5:20 |
| 2 km | 5:20 | 10:40 |
| 3 km | 5:20 | 16:00 |
| 4 km | 5:20 | 21:20 |
| 5 km | 5:20 | 26:40 |
| 6 km | 5:20 | 32:00 |
| 7 km | 5:20 | 37:20 |
| 8 km | 5:20 | 42:40 |
| 9 km | 5:20 | 47:59 |
| 10 km | 5:20 | 53:19 |
| 11 km | 5:20 | 58:39 |
| 12 km | 5:20 | 1:03:59 |
| 13 km | 5:20 | 1:09:19 |
| 14 km | 5:20 | 1:14:39 |
| 15 km | 5:20 | 1:19:59 |
| 16 km | 5:20 | 1:25:19 |
| 17 km | 5:20 | 1:30:39 |
| 18 km | 5:20 | 1:35:59 |
| 19 km | 5:20 | 1:41:19 |
| 20 km | 5:20 | 1:46:39 |
| 21 km | 5:20 | 1:51:59 |
| 22 km | 5:20 | 1:57:19 |
| 23 km | 5:20 | 2:02:39 |
| 24 km | 5:20 | 2:07:59 |
| 25 km | 5:20 | 2:13:19 |
| 26 km | 5:20 | 2:18:39 |
| 27 km | 5:20 | 2:23:58 |
| 28 km | 5:20 | 2:29:18 |
| 29 km | 5:20 | 2:34:38 |
| 30 km | 5:20 | 2:39:58 |
| 31 km | 5:20 | 2:45:18 |
| 32 km | 5:20 | 2:50:38 |
| 33 km | 5:20 | 2:55:58 |
| 34 km | 5:20 | 3:01:18 |
| 35 km | 5:20 | 3:06:38 |
| 36 km | 5:20 | 3:11:58 |
| 37 km | 5:20 | 3:17:18 |
| 38 km | 5:20 | 3:22:38 |
| 39 km | 5:20 | 3:27:58 |
| 40 km | 5:20 | 3:33:18 |
| 41 km | 5:20 | 3:38:38 |
| 42 km | 5:20 | 3:43:58 |
| 42.195 km | 1:02 | 3:45:00 |
Every mile split for a 3:45:00 marathon
Many marathons mark both units. A mile marker arriving between two kilometre markers gives you an extra chance to check the plan without waiting for the next kilometre.
| Marker | Segment time | Elapsed |
|---|---|---|
| 1 mi | 8:35 | 8:35 |
| 2 mi | 8:35 | 17:10 |
| 3 mi | 8:35 | 25:45 |
| 4 mi | 8:35 | 34:20 |
| 5 mi | 8:35 | 42:54 |
| 6 mi | 8:35 | 51:29 |
| 7 mi | 8:35 | 1:00:04 |
| 8 mi | 8:35 | 1:08:39 |
| 9 mi | 8:35 | 1:17:14 |
| 10 mi | 8:35 | 1:25:49 |
| 11 mi | 8:35 | 1:34:24 |
| 12 mi | 8:35 | 1:42:59 |
| 13 mi | 8:35 | 1:51:34 |
| 14 mi | 8:35 | 2:00:09 |
| 15 mi | 8:35 | 2:08:43 |
| 16 mi | 8:35 | 2:17:18 |
| 17 mi | 8:35 | 2:25:53 |
| 18 mi | 8:35 | 2:34:28 |
| 19 mi | 8:35 | 2:43:03 |
| 20 mi | 8:35 | 2:51:38 |
| 21 mi | 8:35 | 3:00:13 |
| 22 mi | 8:35 | 3:08:48 |
| 23 mi | 8:35 | 3:17:23 |
| 24 mi | 8:35 | 3:25:58 |
| 25 mi | 8:35 | 3:34:32 |
| 26 mi | 8:35 | 3:43:07 |
| 26.219 mi | 1:53 | 3:45:00 |
Equivalent race times
What a 3:45:00marathon implies at shorter distances, using Riegel's formula t2 = t1 x (d2 / d1) ^ 1.06. Projecting downwards like this is the more trustworthy direction, because marathon fitness generally implies you could run the shorter time. The methodology page sets out where the model stops being reliable.
| Distance | Equivalent time | Pace / km |
|---|---|---|
| 5K | 23:28 | 4:42 /km |
| 10K | 48:55 | 4:53 /km |
| 15K | 1:15:10 | 5:01 /km |
| 10 mile | 1:21:00 | 5:02 /km |
| Half marathon | 1:47:55 | 5:07 /km |
Adjust the goal
If this is not quite your target, the neighbouring goals show what a step in either direction costs per kilometre, and the pace calculator will take any time you type in.
Frequently asked questions
What pace is a 3:45:00 marathon?
A 3:45:00 marathon is 5:20 per kilometre, or 8:35 per mile, held across the full 42.195 km. That averages 11.3 kph or 7.0 mph.
What should my halfway split be for a 3:45:00 marathon?
An even split puts halfway at 1:52:30. Passing halfway on that figure means you have banked nothing, which is the intended state for an even-paced race rather than a warning sign.
What is 3:45:00 marathon pace on a treadmill?
Set the belt to 11.3 kph or 7.0 mph. The treadmill pace converter explains why the grade setting matters and what the published research says about it.
How much time do I lose if I fade in the second half?
Running the second half five percent slower than the first turns a 3:45:00 into 3:50:38, which is 5:38 off the goal. The fade table on this page gives the same figure for two and ten percent.
What 10K time is equivalent to a 3:45:00 marathon?
Riegel's formula puts it at about 48:55. Read that as a model rather than a measurement: it assumes you are equally well trained for both distances.
Last reviewed . Formulas, constants and sources: methodology. Changes to any calculation are logged in the changelog.