A Half Ironman pace chart turns a finish-time goal into swim, bike, run and transition targets. The splits below are realistic examples rather than a universal formula. Athletes with the same total time may distribute it differently according to strengths, course conditions, body size, equipment and race execution.
A 6-hour Half Ironman example might include a 42-minute swim, 11 minutes in transitions, a 3:05 bike split and a 2:02 half marathon. That requires approximately 2:13/100 m in the swim, 29.2 km/h on the bike and 5:47/km on the run. Use the chart as a planning baseline, then adapt it to your course and ability.
Half Ironman splits by finish time
| Finish | Swim | Transitions | Bike | Run |
|---|---|---|---|---|
| 4:30 | 0:32 | 0:08 | 2:20 | 1:30 |
| 5:00 | 0:36 | 0:09 | 2:35 | 1:40 |
| 5:30 | 0:39 | 0:10 | 2:50 | 1:51 |
| 6:00 | 0:42 | 0:11 | 3:05 | 2:02 |
| 6:30 | 0:45 | 0:12 | 3:20 | 2:13 |
| 7:00 | 0:48 | 0:13 | 3:35 | 2:24 |
| 7:30 | 0:51 | 0:14 | 3:50 | 2:35 |
| 8:00 | 0:54 | 0:15 | 4:05 | 2:46 |
| 8:30 | 0:57 | 0:16 | 4:20 | 2:57 |
Required pace and speed
| Finish | Swim /100m | Bike km/h | Run /km |
|---|---|---|---|
| 4:30 | 1:41 | 38.6 | 4:16 |
| 5:00 | 1:54 | 34.8 | 4:44 |
| 5:30 | 2:03 | 31.8 | 5:16 |
| 6:00 | 2:13 | 29.2 | 5:47 |
| 6:30 | 2:22 | 27.0 | 6:18 |
| 7:00 | 2:32 | 25.1 | 6:50 |
| 7:30 | 2:41 | 23.5 | 7:21 |
| 8:00 | 2:51 | 22.0 | 7:52 |
| 8:30 | 3:00 | 20.8 | 8:23 |
These examples assume standard distances and a relatively balanced athlete. Wind, elevation, currents, transition layout and course measurement can change every discipline.
How to build your own split plan
Swim + T1 + Bike + T2 + Run = Total finish time
Always include realistic transitions. A plan that adds only the three discipline splits is incomplete.
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Estimate the swim
Use repeated open-water or continuous pool efforts, then add margin for navigation and conditions.
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Set a sustainable bike target
Use long-ride power, heart rate and position—not your best 90 km average speed.
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Predict the run from bricks
Open half-marathon pace is usually too optimistic after 90 km of cycling.
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Add transition and stop time
Include wetsuit removal, equipment changes, toilets and aid stations.
How to choose a realistic goal
- Use several recent sessions rather than one exceptional performance.
- Adjust for elevation, road surface, wind, water conditions and expected heat.
- Base the run on brick durability rather than an open race alone.
- Create an A goal, expected B goal and difficult-conditions C goal.
- Leave enough margin to avoid unsafe pacing against the cutoff.
How course conditions change the chart
| Condition | Likely effect | Best response |
|---|---|---|
| Choppy swim | Slower pace and more navigation | Use effort, draft legally and sight efficiently |
| Hilly bike | Lower average speed | Control power spikes and descend safely |
| Strong wind | Large speed variation | Hold effort rather than chasing km/h |
| Hot run | Higher heart rate and pace loss | Reduce early pace and cool proactively |
| Long transitions | Several extra minutes | Practise route and organization |
Why the bike split controls the run
The fastest possible bike is rarely the fastest overall race. Excessive bike intensity raises carbohydrate use and muscular fatigue, making the run deteriorate. Triathletes using power should aim for stable output and minimal surging rather than chasing average speed.
A bike split that is five minutes slower can produce a run that is twenty minutes faster. Judge cycling success by the entire race result.
Using power for Half Ironman pacing
Many experienced athletes race around a moderate fraction of FTP, but the correct target depends on training volume, durability, course and expected duration. Do not copy a universal percentage without confirming it in long bricks. Use normalized power, variability and RPE together.
For exact duration-based watt, IF and TSS targets, use our Half Ironman bike pacing strategy. It shows why the same FTP percentage creates a different race load for a 2:30 and a 4:00 bike split.
- Start below target for the opening 10–20 minutes.
- Avoid repeated power spikes on short hills.
- Stay aero only while the position remains sustainable and safe.
- Review how target power affected running in training.
Why open half-marathon pace is misleading
Most athletes run slower after 90 km of cycling than in an open half marathon. The gap depends on bike pacing, heat, fueling, training age and durability. A small gap for an experienced athlete can become a large one when the bike was overpaced.
| Open half marathon | Possible 70.3 run range | Context |
|---|---|---|
| 1:30 | 1:36–1:50 | Strong durability and execution needed |
| 1:45 | 1:52–2:10 | Common trained age-group range |
| 2:00 | 2:08–2:30 | Depends heavily on bike and heat |
| 2:15 | 2:24–2:50+ | Run-walk may be effective |
Illustrative ranges only. Use your own brick and race data.
Can a run-walk strategy be faster?
Yes. Planned 20–60-second walks at aid stations can support cooling, drinking and consistent form. The strategy works best when started early rather than used only after complete fatigue. Keep walking purposeful and resume running before comfort becomes a long stop.
How much time should transitions take?
| Athlete | Combined T1 + T2 | Priority |
|---|---|---|
| Competitive | 5–8 min | Simple and rehearsed |
| Prepared age-grouper | 8–12 min | Calm organization |
| First-time athlete | 10–18+ min | Avoid mistakes and rushed movement |
Course layout can make even excellent transitions slow. Practise using Triathlon Transitions Explained.
Fueling the target pace
A pace chart assumes the athlete can supply enough carbohydrate and fluid. Many Half Ironman athletes practise approximately 60–90 g of carbohydrate per hour on the bike, followed by a lower individualized run intake. The correct amount depends on tolerance and intensity.
Use How Many Carbs per Hour? and Electrolytes for Endurance Athletes.
For the complete 70.3 execution sequence—from the day-before plan and race breakfast through bike fueling, run intake, heat adjustments and aid-station logistics—use the Half Ironman Nutrition Plan.
Three example athlete profiles
Strong swimmer
May gain only a few minutes from harder swimming but risk more fatigue. Use the advantage to start the bike calmly.
Strong cyclist
Can ride a fast split, but the best target is the power that still permits a controlled half marathon.
Strong runner
Should resist assuming open pace is available after an aggressive bike. Protect the discipline where time can unravel fastest.
Training for your target
The 20-week Half Ironman plan provides a structured build. Compare your goal with average Half Ironman times, but avoid treating an average as a requirement.
Frequently asked questions
What is a good Half Ironman time?
A good time reflects your age, course, experience and goal. Finishing comfortably can be an excellent first result.
Is sub-6 hours realistic?
It is realistic for many trained age-group athletes, but requires balanced discipline fitness and reliable fueling.
Should I target exact bike speed?
No. Wind and elevation change speed. Power, heart rate and effort are better pacing controls.
Do transition times count?
Yes. Both transitions are included in the official finish time.
How accurate is a pace chart?
It is a planning model. Accuracy improves when you replace generic splits with course-specific training data.
Should my fastest discipline receive the most aggressive target?
Not necessarily. The best split distribution minimizes total race time without damaging later disciplines.
Final verdict
Use the Half Ironman pace chart to connect a goal with realistic discipline demands. Then personalize the splits using training data, course conditions, bike durability, transition practice and nutrition. The best target protects the run rather than maximizing one impressive bike split.
These splits become useful only when they are translated into decisions. The Triathlon Race Day Guide explains how to combine a 70.3 target with race-morning logistics, effort ceilings, transitions, fueling and contingency plans.
Split examples are mathematical planning scenarios for the standard 1.9 km, 90 km and 21.1 km distances. Confirm the exact course and cutoff rules in the event athlete guide.
Combine your swim, bike, run and transition estimates in the triathlon race time calculator. If you want the entire build organized week by week, use our beginner half-distance triathlon training plan.
Continue planning with our complete set of triathlon calculators and race-planning tools.
A pace chart describes the outcome, not the preparation. Use our Half Ironman training guide to build the weekly volume, race-specific sessions, bricks and fueling practice required to make your target splits realistic.
