Breaking 3:45 at the Boston Marathon
Even splits would be 5:20/km (8:35/mi). But Boston Marathon isn't flat-even — the plan below redistributes the same finish time across the course the way experienced runners actually race it.
How to pace this course
0–8 km
Steep early descent — resist the free speed
5:15/km (8:27/mi)
8–26 km
Rolling, gradual net downhill
5:18/km (8:32/mi)
26–34 km
The Newton hills, ending at Heartbreak Hill
5:34/km (8:58/mi)
34–42.2 km
Downhill into Boston — if the quads survived
5:15/km (8:27/mi)
Split table
| Checkpoint | Split | Elapsed | Pace at this point |
|---|---|---|---|
| 5 km | 26:15 | 26:15 | 5:15/km |
| 10 km | 26:21 | 52:36 | 5:18/km |
| 15 km | 26:31 | 1:19:07 | 5:18/km |
| 20 km | 26:31 | 1:45:37 | 5:18/km |
| Half | 5:49 | 1:51:26 | 5:18/km |
| 25 km | 20:42 | 2:12:08 | 5:18/km |
| 30 km | 27:35 | 2:39:43 | 5:34/km |
| 35 km | 27:31 | 3:07:14 | 5:15/km |
| 40 km | 26:15 | 3:33:29 | 5:15/km |
| Finish | 11:31 | 3:45:00 | 5:15/km |
Print this table or write the elapsed times on your arm — GPS pace is least reliable exactly when you need it most.