Built by Tommo, Verus founder — free to use, no account required.
Ironman Training Duration Calculator
70.3 or full distance — the real timeline for three disciplines at once.
Ironman 70.3 Training Duration Calculator
Pick where you're starting from, and see how many weeks the block actually takes — and, with a race date, the week to start.
Distance
Where you're starting from
Training block
16-20 weeks
Base
6 weeks
Raise weekly volume and consistency. No heroics — this is where most of the injury risk in the whole block gets managed.
Build
9 weeks
The longest sessions, threshold work, and race-pace effort layered into them.
Peak
3 weeks
The hardest stretch of the block — the volume and intensity both near their maximum.
Taper
2 weeks
Volume drops sharply, intensity mostly stays. This is where the training becomes fitness.
General planning guidance based on well-established, mainstream training-week ranges — not a personalised coaching plan. Uses the longer end of the range for the phase breakdown and start date, since starting a little early costs a taper week and starting a little late costs the race.
Use It On A Real Race
About This Tool
Training for three disciplines at once doesn't just add up the time each one would take alone — it depends on how much multisport base you're already carrying. This calculator covers both 70.3 and full-distance Ironman, and asks where you're actually starting from: new to triathlon entirely, or an experienced 70.3 finisher building to your first full distance.
How To Use It
- Choose 70.3 or Full Distance.
- Pick the description that matches your current multisport training.
- Add a race date if you have one, to get a start-by date.
- Read the weeks needed and the base/build/peak/taper breakdown across swim, bike and run.
Training for three disciplines at once doesn't just add up the time each would take alone — it depends on how much multisport base you're already carrying into the block. The calculator above covers both 70.3 and full distance, and asks where you're actually starting from rather than assuming you're already a triathlete.
Ironman 70.3 — the four starting points
| Where you are now | Weeks to the start line | What the time is for |
|---|---|---|
| New to multisport | 34-43 weeks | Building a base in all three disciplines from occasional exercise — the longest runway on this page, and the one worth respecting. |
| Regular exercise, can finish a sprint triathlon | 21-26 weeks | Raising volume across swim, bike and run before the specific block begins. |
| Training in all three disciplines, completed an Olympic-distance tri | 16-20 weeks | The athlete most published 70.3 plans are written for. |
| Experienced, recent 70.3, aiming to improve | 12-16 weeks | You have the base — this is about race-specific bike and run volume. |
Full-distance Ironman — the four starting points
| Where you are now | Weeks to the start line | What the time is for |
|---|---|---|
| New to multisport | 52-65 weeks | At least a year, and honestly longer where possible — full-distance training rewards years of aerobic base far more than any single block. |
| Regular multisport athlete, completed Olympic or 70.3 distance | 24-30 weeks | You have a real base to build the full-distance block from. |
| Experienced 70.3 finisher, training consistently | 20-24 weeks | The athlete most published full-distance plans are written for. |
| Experienced full-distance finisher, returning | 16-20 weeks | You know the volume this takes — the block sharpens rather than builds. |
Where the hours actually go
70.3 training typically runs 8-12 hours a week at peak; full-distance training runs 12-18 hours or more. The bike carries the largest single block of time in both — consistent bike volume moves finish time more than any other discipline, which is worth knowing before splitting your week evenly across all three out of habit.
The swim is not where the time is
The swim is usually the smallest fraction of race time in both distances, and the one age-groupers most often over-invest in relative to its return. Train it enough to arrive on the bike comfortable, then put the remaining hours where the race actually is.
Related Tools
Frequently Asked Questions
How long does it take to train for an Ironman 70.3?
16-20 weeks if you're already training across all three disciplines and have completed an Olympic-distance triathlon — that's the athlete most published 70.3 plans are written for. New to multisport, allow eight to ten months to build a genuine base first.
How long does it take to train for a full Ironman?
24-30 weeks for an athlete who's already completed an Olympic or 70.3 distance and trains regularly across all three disciplines. New to multisport, most coaches recommend at least a year of consistent training before attempting the full distance — this is not a race to compress.
Can I train for a 70.3 in 12 weeks?
Only if you're already an experienced triathlete with a recent 70.3 behind you — twelve weeks is a sharpening block for someone with the base, not a building block from nothing. New to the distance, twelve weeks raises real injury and burnout risk across three disciplines at once.
How many hours a week is Ironman training?
70.3 training typically runs 8-12 hours a week at peak; full-distance training runs 12-18 hours or more, with the bike taking the largest share of both. This is the commitment that catches people out about triathlon specifically — it's not one long session, it's three disciplines' worth of volume every week for months.
Which discipline should I prioritise in Ironman training?
The one you're weakest at, almost always — but the bike carries the largest block of race time in both distances, so consistent bike volume has the biggest single effect on finish time. The swim is usually the smallest fraction of race time and the one most age-groupers over-invest in relative to its return.