What is a cutoff buffer?
It is the time between a calculated arrival and the official cutoff. A positive buffer is not a guarantee: climbs, weather, navigation, queues and physical problems can consume it.
Checkpoint and cutoff planning
Ultra Cutoff Planner
Turn official checkpoint distances and elapsed-time cutoffs into arrival estimates, stop-adjusted buffers, and an ink-friendly pace band.
Race and pace
Enter official checkpoint distances and elapsed-time cutoffs from the current race guide.
Checkpoints
Printable checkpoint plan
My ultramarathon
Constant moving pace: 9.0 min/km
Finish ETA
21:15
100.0 km
Tightest buffer
+45m
Across entered checkpoints
Planned stops
15 min
All checkpoint stops combined
First missed cutoff
None
Under this arithmetic scenario
| Checkpoint | Distance | Planned arrival | Departure | Official cutoff | Buffer | Latest segment pace |
|---|---|---|---|---|---|---|
| Aid 1 | 25.0 km | 09:45 | 09:50 | 10:30 | +45m | 10:48/km |
| Aid 2 | 50.0 km | 13:35 | 13:45 | 15:00 | +1h 25m | 10:36/km |
| Finish | 100.0 km | 21:15 | 21:15 | Day 2 · 00:00 | +2h 45m | 10:36/km |
“Latest segment pace” assumes arrival at the preceding cutoff and includes that checkpoint's planned stop before the next segment. Real terrain and conditions are not modeled. Verify every cutoff against the current official race guide.
Build the Table from Official Information
Copy checkpoint distances and cutoff times from the current organizer guide. Do not reuse last year's spreadsheet without checking for course and schedule changes. Enter every cutoff as elapsed time from the start.
Interpret the Buffer Carefully
The planner applies one moving pace across the course, then adds each stop to later arrivals. That makes the arithmetic transparent, but not terrain-aware. Compare several conservative scenarios and use the aid-station strategy guide to define what actually needs to happen at each stop.
Frequently Asked Questions
Should cutoff times be entered as clock times or elapsed time?
Enter elapsed hours from the race start. The planner combines those values with the start clock to display local cutoff times, including later days.
How are checkpoint stops handled?
A stop is added after arrival at its checkpoint and therefore delays every later arrival. The finish stop has no effect unless another checkpoint follows it.
Does the planner account for elevation?
No. It uses a constant moving pace. Build conservative scenarios from course-specific training and use official route information rather than treating the output as a prediction.