Races · Thailand
Bangsaen21 2026 is on Sunday 20 December 2026 (Bangkok, Thailand). That is 9 weeks from today.
9 weeks to go
Organisers sometimes move a date. Check the official site before you book travel.
Training plan
Counted back from race day. These are the dates the plan would run on if you started it now.
9 weeks is enough for a shorter half marathon plan (the minimum is 8). Start this week to use all of it.
Pick Bangsaen21 as the goal in the app. The plan counts back from race day and moves when you miss a run.
This is the layout the plan builder starts from. In the app it shifts with how long you have been running, and the week moves when you miss a run.
Fill in your weekly distance and your longest recent run. The check runs on the same engine that builds the plan and says whether this race fits, before you pay for an entry.
Free · no signup
Computed by the same engine that builds Runapt plans — so this can never clear a race the plan builder would block.
Pace
Even pace from start to finish, without stops. Training paces are slower than this on most days.
| Finish time | Per km | Per mile |
|---|---|---|
| 1:30:00 | 4:16 | 6:52 |
| 1:45:00 | 4:59 | 8:01 |
| 2:00:00 | 5:41 | 9:09 |
| 2:15:00 | 6:24 | 10:18 |
| 2:30:00 | 7:07 | 11:27 |
| 2:45:00 | 7:49 | 12:35 |
Bangsaen21 2026 is on Sunday 20 December 2026 (Bangkok, Thailand). That is 9 weeks from today.
Bangsaen21 offers these distances: Half Marathon.
The Runapt half marathon plan runs 14 weeks as standard and 8 weeks at the shortest. That assumes you already run a few times a week. Starting from zero takes longer.
9 weeks is enough for a shorter half marathon plan (the minimum is 8). Start this week to use all of it.
Entries are handled by the organiser at bangsaen21.com. Runapt does not sell race entries; it builds the training plan.
More races
Download Runapt and build your first training week. The free plan has no time limit.
Or start on the web