Cutoff calculator

Check your pace against the swim, bike and finish cutoffs for a Full and a Half IRONMAN. See the margin you have at each one and the slowest pace that still makes it.

Distance

I know my swim as

Swim pace

/100 m

m:ss, for example 2:15

T1, swim to bike

m:ss

Bike speed

km/h

T2, bike to run

m:ss

Run pace, including walking

/km

m:ss. Use your average for the whole run.

Will you make the cutoffs?

Yes, with room to spare

All times are measured from your own start, and the bike cutoff includes the swim and T1.

Swim, cutoff 2:20:00: 1:25:30, 54:30 to spare
Bike, cutoff 10:30:00: 9:01:30, 1:28:30 to spare
Finish, cutoff 17:00:00: 14:43:06, 2:16:54 to spare
Slowest swim pace that makes it: 3:41 /100 m
Slowest bike speed that makes it: 20.1 km/h
Slowest run pace that makes it: 11:15 /km

How it works

The standard cutoffs

These are the typical limits for IRONMAN races, usually measured from your own start (your time in a rolling start, not the gun). The race athlete guide sets the official limits:

Full: swim 2:20, swim plus T1 plus bike 10:30, finish 17:00.
Half: swim 1:10, swim plus T1 plus bike 5:30, finish 8:30.

The bike cutoff is cumulative. It is the clock time at which you must be off the bike, so it includes the swim and T1. The finish cutoff includes everything.

Some races differ. A hard or hot course can have a shorter bike limit, and many races add intermediate checkpoints on the bike and run. The athlete guide for your race is the authority. Check it before you rely on any calculator, including this one.

How the margins are worked out

Your swim time is the swim distance times your pace per 100 m, or the time you enter. The bike cutoff clock reads swim plus T1 plus bike time, and the finish clock adds T2 and the run. The margin at each cutoff is the cutoff minus your clock time.

The slowest pace that still makes each cutoff holds your other inputs fixed. For the bike it is the bike distance divided by the time left after your swim and T1. For the run it is the time left after the bike and T2, divided by the run distance. A margin under 15 minutes at the bike or finish, or under 5 at the swim, shows as a warning, because one flat tyre or a bad patch on the run can spend it.

For the run, enter your average pace including any walking at aid stations. If you are close, plan with the race time calculator and trim minutes from your changes with the transition time calculator.

What to do if the margin is thin

The bike cutoff is where most athletes get caught, so a thin bike margin is the one to act on. Swim steadier rather than harder, keep T1 short, and look at your average speed on a long training ride rather than your best.

Read the athlete guide for the race you picked, then work backwards from race day with the race week checklist. You can search for your race to see its date and details.

Sources

IRONMAN Arizona course preview: 10:30 limit for swim, T1 and bike, measured from each athlete's own start.
IRONMAN Santa Rosa course preview: 2:20 swim limit with a full window for every athlete.
IRONMAN Chattanooga Half course preview: 8:30 Half limit and the 5:30 swim, T1 and bike limit.
Marathon Handbook, IRONMAN cutoff times: a secondary summary of the standard limits. The 2026 IRONMAN Competition Rules (PDF) state only that swim, bike and run cutoffs are published in each event's athlete guide, so the standard limits here rest on the race previews quoted above and are typical, not guaranteed.
IRONMAN athlete guide for your specific race: the final authority, with any intermediate checkpoints.

Questions

What are the cutoff times for a Full IRONMAN?

The standard Full cutoffs are 2:20 for the swim, 10:30 for swim plus T1 plus bike, and 17:00 for the finish. Most races count these from your own start, but some count the finish from the last athlete entering the water or use a fixed clock time. IRONMAN publishes the limits per race, so check the athlete guide for yours.

What are the cutoff times for a Half IRONMAN?

The standard Half cutoffs are 1:10 for the swim, 5:30 for swim plus T1 plus bike, and 8:30 for the finish. Most races count these from your own start, but some set different limits or count from a fixed time. IRONMAN publishes the limits per race, so check the athlete guide for yours.

Is the cutoff measured from the gun or from my start?

In a rolling start, IRONMAN measures from the moment you cross the start line and enter the water, so your cutoffs are your own. In a mass start, the clock starts at the gun for everyone.

Does the bike cutoff include the swim?

Yes. The bike cutoff is cumulative, so it covers the swim, T1 and the bike. A 10:30 bike cutoff in a Full means you must be off the bike 10:30 after you started the swim.

What bike speed do I need to make the cutoff?

It depends on your swim and T1. With a 1:30 swim and a 6 minute T1, a Full needs about 20.2 km/h over 180 km to make a 10:30 bike cutoff. Enter your own numbers above for the exact figure.

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