Chicago Marathon 3:45 pace chart
A 3:45:00 finish at the Chicago Marathon averages 8:35 per mile (5:20 per kilometre) — a fast recreational time, roughly the top quintile of a big-city field. Run at even effort rather than even pace, the easiest mile comes in around 8:27/mi and the hardest around 8:41/mi — about 14 seconds between the two extremes. Holding an identical number on every mile of a course with this profile means running the climbs too hard and the descents too easy. Held at even effort, halfway comes up at 1:52:23 — an almost exactly even split. The hardest mile on the course sits near kilometre 28; at this goal time it should take 8:36/mi, and giving it that time is the difference between finishing Chicago on plan and unravelling in the last hour.
Mile-by-mile targets for 3:45:00
Grade-adjusted splits computed from the Chicago Marathon elevation profile with the Minetti gradient-cost model, scaled so the full course adds up to 3:45:00. Uphill sections get more time, downhills less, at one constant effort throughout.
| Mile | Target /mi | Target /km | Elev Δ | Elapsed |
|---|---|---|---|---|
| 1 | 8:29 | 5:16 | -12 ft (-4 m) | 8:29 |
| 2 | 8:41 | 5:24 | +10 ft (+3 m) | 17:10 |
| 3 | 8:27 | 5:15 | -16 ft (-5 m) | 25:37 |
| 4 | 8:40 | 5:23 | +9 ft (+3 m) | 34:17 |
| 5 | 8:39 | 5:22 | +8 ft (+2 m) | 42:56 |
| 6 | 8:29 | 5:16 | -11 ft (-3 m) | 51:25 |
| 7 | 8:35 | 5:20 | +1 ft (0 m) | 1:00:00 |
| 8 | 8:36 | 5:21 | +2 ft (+1 m) | 1:08:36 |
| 9 | 8:36 | 5:21 | +2 ft (+1 m) | 1:17:12 |
| 10 | 8:39 | 5:23 | +8 ft (+3 m) | 1:25:52 |
| 11 | 8:32 | 5:18 | -5 ft (-1 m) | 1:34:24 |
| 12 | 8:32 | 5:18 | -5 ft (-2 m) | 1:42:56 |
| 13 | 8:30 | 5:17 | -10 ft (-3 m) | 1:51:26 |
| 14 | 8:40 | 5:23 | +9 ft (+3 m) | 2:00:06 |
| 15 | 8:38 | 5:22 | +5 ft (+2 m) | 2:08:44 |
| 16 | 8:30 | 5:17 | -9 ft (-3 m) | 2:17:14 |
| 17 | 8:37 | 5:21 | +4 ft (+1 m) | 2:25:51 |
| 18 | 8:36 | 5:21 | +2 ft (+1 m) | 2:34:27 |
| 19 | 8:35 | 5:20 | 0 ft (0 m) | 2:43:02 |
| 20 | 8:37 | 5:22 | +5 ft (+1 m) | 2:51:40 |
| 21 | 8:31 | 5:18 | -7 ft (-2 m) | 3:00:11 |
| 22 | 8:33 | 5:19 | -5 ft (-1 m) | 3:08:44 |
| 23 | 8:40 | 5:23 | +9 ft (+3 m) | 3:17:24 |
| 24 | 8:36 | 5:20 | +1 ft (0 m) | 3:25:59 |
| 25 | 8:31 | 5:18 | -7 ft (-2 m) | 3:34:31 |
| 26 | 8:39 | 5:22 | +7 ft (+2 m) | 3:43:10 |
| 26.2 | 8:25 | 5:14 | -4 ft (-1 m) | 3:45:00 |
Frequently asked questions
What pace is a 3:45 marathon?
A 3:45:00 marathon is 8:35 per mile or 5:20 per kilometre held for the full 26.2 miles (42.195 km). On the Chicago Marathon specifically, the elevation profile means even effort produces uneven splits — the table on this page gives the target for every mile.
What should my halfway split be for a 3:45 at the Chicago Marathon?
1:52:23. That is the grade-adjusted halfway target for this course, not simply half of 3:45:00 — it accounts for where the climbing sits. Reaching the half meaningfully faster than this on this course usually means you have spent the effort you need for the closing miles.
Should I run even splits at the Chicago Marathon?
Even effort at a 3:45 goal produces splits between 8:27 and 8:41 per mile — about 14 seconds between the easiest and hardest one. Grade-adjusted pacing gives back time on the descents and spends it on the climbs, which is what running an even physiological effort actually looks like on a course with this profile.
How are these Chicago Marathon splits calculated?
Each mile is weighted by its gradient using the Minetti et al. (2002) cost-of-running polynomial, which measures the metabolic cost of running at grades from −45% to +45%. The total is then scaled so the whole course adds up to 3:45:00. Uphill sections get more time and downhill sections less, at a constant effort throughout.
Is 3:45 a realistic marathon goal?
3:45 is a fast recreational time, roughly the top quintile of a big-city field. Whether it is realistic for you depends on your recent race results and weekly volume rather than on the number itself — the race-time predictor on this site will convert a recent 5K, 10K or half-marathon result into a marathon estimate using the Riegel power-law model.