Long-course race safety
Ironman Cutoff Calculator
Check whether your full Ironman or 70.3 race plan clears the swim, bike, and finish cutoffs with enough buffer to stay calm late in the day.
Swim pace / 100m
Run pace / km
Cutoff safe
48m
Smallest buffer at swim.
Swim
Clock 01:31:50
48m
buffer
Bike
Clock 09:00:39
1h 29m
buffer
Finish
Clock 14:24:07
2h 35m
buffer
Edit official cutoffs
Use the defaults for planning, then replace these with your race athlete-guide times. Some venues use different intermediate rules or course-closure clocks.
What the result means
The swim checkpoint compares your swim split plus wave offset against the swim cutoff. The bike checkpoint compares swim + T1 + bike against the cumulative bike cutoff. The finish checkpoint compares the full day against the final cutoff.
Green buffers are planning room, not permission to ignore race rules. Always check the official athlete guide because IRONMAN rules state that venue-specific guides provide cutoff details and exceptions.
- Official event guides can vary by venue, wave, weather, road closure, and race director instruction.
Full Ironman (140.6) cutoff times
Common full-distance planning defaults, measured as a cumulative clock from your individual start. Cutoffs are course-specific — always confirm the numbers in your event's athlete information guide.
| Checkpoint | Distance | Cutoff from start | What it covers |
|---|---|---|---|
| Swim | 3.8 km / 2.4 mi | 2:20 | Time to exit the water |
| Bike | 180 km / 112 mi | 10:30 | Swim + T1 + bike, cumulative |
| Finish | 42.2 km / 26.2 mi | 17:00 | Overall course closure |
Many venues also enforce intermediate bike and run cut-offs at specific aid stations. A 17:00 finisher must average roughly a 13:45 min/mi marathon after the swim and bike.
Ironman 70.3 (half) cutoff times
Common half-distance planning defaults as a cumulative clock from your start. As with full-distance racing, official event guides can vary these by venue.
| Checkpoint | Distance | Cutoff from start | What it covers |
|---|---|---|---|
| Swim | 1.9 km / 1.2 mi | 1:10 | Time to exit the water |
| Bike | 90 km / 56 mi | 5:30 | Swim + T1 + bike, cumulative |
| Finish | 21.1 km / 13.1 mi | 8:30 | Overall course closure |
An 8:30 finisher has roughly 3:00 for the half marathon after clearing the bike cutoff — about a 13:45 min/mi run pace with transitions included.
How to read cutoff buffer
Green does not mean careless. A useful long-course plan keeps buffer at the swim exit, bike cutoff, and finish line because small delays stack up: crowds, bathroom stops, bottle drops, hot run pacing, or a slow transition can all spend minutes.
- Check swim, bike, and finish clocks separately.
- Use wave offset only when it matches your event's cutoff rules.
- Recalculate after changing bike effort or run pace.
Example race read
A full-distance athlete projecting a 1:35 swim, 7:10 bike including T1, and 5:25 marathon may look safe overall, but the bike cutoff can still be the pressure point if the course closes at a fixed clock time.
Common mistakes
The most common mistake is judging only the final 17-hour or 8:30 clock. Cutoff risk often appears earlier on the swim or bike, especially when a nervous swim, long T1, headwind, or mechanical delay removes the buffer before the run begins.
Frequently asked questions
- What does an Ironman cutoff calculator do?
- It compares your projected swim, bike, and finish clock against cutoff times so you can see how much buffer you have at each checkpoint.
- Are Ironman cutoff times always the same?
- No. Common planning defaults are useful, but official race cutoffs can vary by venue and athlete guide. Always enter the cutoffs from your event.
- What is the common 70.3 cutoff?
- Many Ironman 70.3 events use a 1:10 swim cutoff, 5:30 cumulative bike cutoff, and 8:30 finish cutoff, but event guides can differ.
- What is the common full Ironman cutoff?
- Many full-distance events use a 2:20 swim cutoff, about 10:30 cumulative bike cutoff, and 17:00 finish cutoff, but course-specific rules matter.
- Should I include wave offset?
- Yes if your event uses a published course-closure clock or final-athlete start reference that makes your personal start later than the cutoff clock.
Use official race-guide times
The calculator starts with common planning defaults, but it is deliberately editable. IRONMAN's competition rules say event-specific athlete information guides provide cutoff guidance and exceptions, so the trusted workflow is: open your event guide, copy the swim, bike, and finish cutoffs, then check your buffer here.
Next planning step
If your cutoff buffer is tight, do not guess. Build a more conservative full race plan, then check bike power, run durability, and fueling separately.
Trust and methodology
How this page should be used
Last updated
August 8, 2026
Maintained by
M Imtinan Farooq
Status
Planning estimate, not a race guarantee
Formula summary
Checkpoint buffer = official cutoff clock minus projected checkpoint clock.
Key assumptions
Entered paces, transitions, wave offset, and cutoff fields match the athlete guide.
Limitations
Venue-specific athlete guides and race-day officials override planning defaults.