Sub-1:45 Half Marathon
A sub-1:45 half marathon means 8:01 per mile (4:59 per kilometre) across 13.1 miles. That is a 42.6 VDOT performance: a real target that rewards consistent weeks far more than heroic single sessions.
Mile-by-mile splits for 1:45:00
The half marathon punishes early bravery less brutally than the marathon, but it still punishes it. The even-split table below holds 8:01 per mile for all 13.1 miles and passes halfway at 52:30 on the way to 1:45:00. Treat those numbers as a ceiling for the opening miles, not a target to beat.
The negative-split version opens at 8:05 per mile through halfway (53:02) and closes at 7:56. Over 13 miles that is a small, survivable debt to take on early and a large psychological win to collect late — you spend the last three miles passing people instead of being passed.
Even splits — 8:01 per mile
| Mile | Pace | Split | Elapsed |
|---|---|---|---|
| 1 | 8:01 | 8:01 | 8:01 |
| 2 | 8:01 | 8:01 | 16:01 |
| 3 | 8:01 | 8:01 | 24:02 |
| 4 | 8:01 | 8:01 | 32:02 |
| 5 | 8:01 | 8:01 | 40:03 |
| 6 | 8:01 | 8:01 | 48:03 |
| 7 | 8:01 | 8:01 | 56:04 |
| 8 | 8:01 | 8:01 | 1:04:05 |
| 9 | 8:01 | 8:01 | 1:12:05 |
| 10 | 8:01 | 8:01 | 1:20:06 |
| 11 | 8:01 | 8:01 | 1:28:06 |
| 12 | 8:01 | 8:01 | 1:36:07 |
| 13 | 8:01 | 8:01 | 1:44:07 |
| 13.1 | 8:01 | 0:53 | 1:45:00 |
Even pacing: 8:01 per mile for all 13.1 miles, finishing in 1:45:00.
Slight negative split — 8:05 out, 7:56 home
| Mile | Pace | Split | Elapsed |
|---|---|---|---|
| 1 | 8:05 | 8:05 | 8:05 |
| 2 | 8:05 | 8:05 | 16:11 |
| 3 | 8:05 | 8:05 | 24:16 |
| 4 | 8:05 | 8:05 | 32:22 |
| 5 | 8:05 | 8:05 | 40:27 |
| 6 | 8:05 | 8:05 | 48:32 |
| 7 | 8:01 | 8:01 | 56:33 |
| 8 | 7:56 | 7:56 | 1:04:29 |
| 9 | 7:56 | 7:56 | 1:12:25 |
| 10 | 7:56 | 7:56 | 1:20:21 |
| 11 | 7:56 | 7:56 | 1:28:16 |
| 12 | 7:56 | 7:56 | 1:36:12 |
| 13 | 7:56 | 7:56 | 1:44:08 |
| 13.1 | 7:56 | 0:52 | 1:45:00 |
One percent either side of even: 8:05 per mile through halfway (53:02), then 7:56 home. Same 1:45:00 finish. The mile that straddles halfway blends both paces.
Per kilometre — 4:59 per km
| Km | Pace | Split | Elapsed |
|---|---|---|---|
| 1 | 4:59 | 4:59 | 4:59 |
| 2 | 4:59 | 4:59 | 9:57 |
| 3 | 4:59 | 4:59 | 14:56 |
| 4 | 4:59 | 4:59 | 19:54 |
| 5 | 4:59 | 4:59 | 24:53 |
| 6 | 4:59 | 4:59 | 29:52 |
| 7 | 4:59 | 4:59 | 34:50 |
| 8 | 4:59 | 4:59 | 39:49 |
| 9 | 4:59 | 4:59 | 44:48 |
| 10 | 4:59 | 4:59 | 49:46 |
| 11 | 4:59 | 4:59 | 54:45 |
| 12 | 4:59 | 4:59 | 59:43 |
| 13 | 4:59 | 4:59 | 1:04:42 |
| 14 | 4:59 | 4:59 | 1:09:41 |
| 15 | 4:59 | 4:59 | 1:14:39 |
| 16 | 4:59 | 4:59 | 1:19:38 |
| 17 | 4:59 | 4:59 | 1:24:36 |
| 18 | 4:59 | 4:59 | 1:29:35 |
| 19 | 4:59 | 4:59 | 1:34:34 |
| 20 | 4:59 | 4:59 | 1:39:32 |
| 21 | 4:59 | 4:59 | 1:44:31 |
| 21.1 | 4:59 | 0:29 | 1:45:00 |
Even pacing in metric: 4:59 per kilometre across 21.1 km.
Are you ready for a sub-1:45 half marathon?
| Distance | Equivalent time | Pace /mi | Pace /km |
|---|---|---|---|
| 5K | 22:51 | 7:21 | 4:34 |
| 10K | 47:24 | 7:38 | 4:44 |
| Half Marathon — your goal (1:45:00) | 1:45:04 | 8:01 | 4:59 |
| Marathon | 3:37:59 | 8:19 | 5:10 |
Equivalent times are computed from the rounded VDOT of 42.6, so the half marathon row lands within a few seconds of 1:45:00 rather than exactly on it. That is rounding, not a different prediction.
To go under 1:45:00 for the half you need 8:01 per mile, and you should already be capable of roughly a 22:51 5K or a 47:24 10K. If your 10K is already there and the half is not, you have a durability gap rather than a speed gap — the second hour is the part that needs training.
This is an eminently winnable goal, and the arithmetic is friendly: 8:01 per mile is well clear of your threshold pace of 7:47, so race pace should feel controlled for the first eight miles. The two things that decide it are unglamorous — a long run that reaches 11 or 12 miles comfortably, and easy days actually run easy, around 9:21 per mile, so the quality sessions land on fresh legs. Most runners who miss a sub-1:45 half were fit enough and simply ran the opening two miles too hard.
Sub-1:45 is eight-minute miles with one second of grace — 8:01, held for 13.1 miles, halfway at 52:30. It is among the most-set goals in the distance because both of its doors are honest: arrive via a 47:24 10K and the speed is proven; arrive via patient volume and the strength is. What converts either into 1:45:00 is the unglamorous middle — miles six through ten, held at 8:01 while the mind negotiates — and the weekly threshold appointment at 7:47 that makes that pace boring before the race arrives.
Where do you stand right now?
Enter a race you have actually run and this will tell you where you stand against the 42.6 VDOT a sub-1:45 half marathon requires — your score, the target, and the gap. Nothing is stored or sent anywhere.
Training paces for a sub-1:45 half marathon
These are the paces that go with the 42.6 VDOT a sub-1:45 half marathon requires. Treat them as day-one numbers — they should change as you do. The most common mistake is running the easy days too hard: 9:21 per mile is not a suggestion, it is what makes the quality sessions possible.
| Pace | min/mi | min/km | Where it is used |
|---|---|---|---|
| Easy | 9:21 | 5:49 | Most of your week |
| Marathon | 8:19 | 5:10 | Race-pace work |
| Threshold | 7:47 | 4:50 | Tempo / cruise intervals |
| Interval | 7:12 | 4:28 | VO₂max work |
| Repetition | 6:45 | 4:12 | Speed and form |
| Recovery | 11:19 | 7:02 | Shake-out jogs |
Easy pace is a range rather than a point — Daniels defines it as 59–74% of VO₂max, which for the fitness behind a sub-1:45 half marathon runs from 8:57 to 10:43 per mile. The single easy figure below is the 70% value.
Paces that move when you do.
The table above is a static snapshot of the VDOT 42.6 behind a sub-1:45 half marathon. Why Not recalculates the same six paces after every run you log — pulling them tighter as you get fitter, easing them off when you are cooked, and rebuilding the plan around the weeks life actually gave you.
Build my sub-1:45 planSub-1:45 half marathon FAQ
8:01 per mile, or 4:59 per kilometre, held for 13.1 miles, with halfway at 52:30. A slightly conservative opening at 8:05 followed by 7:56 gets you the same 1:45:00.
VDOT 42.6 — the score behind every pace on this page.
For most runners with a base, yes, within one structured block. Equivalent performances are about a 22:51 5K or a 47:24 10K. If you can already run a hard 10K near that, extending the effort is the whole job.
Respect the first three miles. Race pace of 8:01 is well clear of your threshold pace of 7:47, so it should feel controlled early — if it does not, you are running someone else's race.
Easy at 9:21 per mile (range 8:57 to 10:43), marathon pace at 8:19, threshold at 7:47, intervals at 7:12, repetitions at 6:45, and recovery at 11:19.
Every number on this page is computed from our own implementation of the Daniels–Gilbert formulas published in Daniels' Running Formula (Jack Daniels & Jimmy Gilbert) — the same library the Why Not app runs. Nothing is transcribed from the book's tables, and this site is not affiliated with or endorsed by the authors. Equivalent times assume you train appropriately for the target distance; that caveat is Daniels' own.
A coach for the price of a coffee run.
A human marathon coach runs $100 to $300 a month and rebuilds your plan when you email them. Why Not runs the same Daniels VDOT engine behind every number on this page and adapts after every workout. A full year of the app costs less than the cheapest month of human coaching.
Start 7 days free