Triathlon splits explained: swim, T1, bike, T2 and run
A triathlon result is five split times that add up to your finish: swim, T1 (the first transition), bike, T2 (the second transition) and run. Each split measures one stretch of the race, so you can compare your swim to your run or to other athletes in the same race. Turn each leg into a pace (per 100 meters, miles per hour, minutes per mile) before comparing, and only compare races of the same distance.
The five splits
| Split | What it measures |
|---|---|
| Swim | Time in the water, from the start to the swim exit timing mat. |
| T1 | The first transition: swim exit to bike start. It covers the run to the bike rack, taking off the wetsuit, putting on shoes and helmet, and getting out on the bike. |
| Bike | Time on the bike course, from the mount line to the dismount line. |
| T2 | The second transition: bike finish to run start. Rack the bike, change shoes, start running. |
| Run | Time from the run start to the finish line. |
Add the five together and you get the finish time. Timing mats sit in slightly different places at different races, so a few seconds of one split can shift into its neighbor. Compare splits within one race, or across races that use the same timing setup, and expect small gaps.
Distances
The common formats, according to the age-group listing on Active.com and World Triathlon, are:
| Format | Swim | Bike | Run |
|---|---|---|---|
| Sprint | 750 m | 20 km | 5 km |
| Olympic (standard) | 1.5 km | 40 km | 10 km |
| Half-distance | 1.9 km | 90 km | 21.1 km |
| Full-distance | 3.8 km | 180 km | 42.2 km |
The half-distance swim is about 1.2 miles, the bike about 56 and the run 13.1. The full-distance swim is about 2.4 miles, the bike 112 and the run 26.2.
Turn each split into a pace
Raw split times only compare legs of equal length, and no two legs are. Convert them:
- Swim: total seconds divided by the swim distance in meters, times 100. That gives time per 100 m.
- Bike: distance in miles divided by hours. That gives miles per hour.
- Run: total minutes divided by miles. That gives minutes per mile.
A made-up half-distance finish shows how it works:
| Split | Time | Pace |
|---|---|---|
| Swim (1.9 km) | 38:00 | 2:00 per 100 m |
| T1 | 4:30 | |
| Bike (56 mi) | 2:55:00 | 19.2 mph |
| T2 | 3:00 | |
| Run (13.1 mi) | 1:49:30 | 8:22 per mile |
| Finish | 5:30:00 |
Illustrative numbers, not a real athlete. The bike is about 53 percent of this finish time and the run about 33 percent, while the swim is about 12 percent.
Which split matters most
A 2025 study in Sports Medicine - Open analyzed 687,696 full-distance age-group finishes from 2002 to 2022. It found that overall finish time correlated more strongly with the bike and run than with the swim: r = 0.88 and 0.89 for women, and 0.89 and 0.90 for men. Those correlations weakened with age, and the swim weakened the most. In plain terms, the swim is the shortest leg, and the bike and run are where race order is mostly decided.
Transitions are small but different in kind. A faster T1 or T2 comes from practice and a plan, not from fitness. Athletes track them separately, and adding them into one transitions number shows how many minutes they cost across races.
What typical finish times look like
The same study lists the average full-distance age-group finish by five-year age group. A few rows:
| Age group | Men (mean) | Women (mean) |
|---|---|---|
| 25-29 | 12:19:28 | 13:07:35 |
| 35-39 | 12:20:21 | 13:19:36 |
| 45-49 | 12:44:21 | 13:43:29 |
| 55-59 | 13:27:46 | 14:18:42 |
Mean overall times for full-distance age-group finishers, 2002 to 2022. Source: Knechtle et al., 2025, Table 1. Course and weather change results a lot, so use these as a range, not a target.
Active.com puts typical finish times at about 4 to 7 hours for a half-distance race and 8 to 17 hours for a full-distance one, which brackets the study's averages.
How to compare your own races
- Compare the same format only. A half-distance run is not a full-distance run.
- Look at each leg as a pace, since raw times of different lengths do not compare.
- Check your rank within your age group for each split, not only your finish place. A strong bike and a weak swim shows up there right away.
- Track T1 and T2 over several races. Course layout changes transition length, so judge by the trend.
- Look at the same course across years to remove the course from the comparison.
How IM Tri Tracker helps
IM Tri Tracker is an independent app for iPhone and Android, not affiliated with any race organizer or timing company. Search a name and it pulls the published full and half-distance results from the supported timing feed, shows the swim, T1, bike, T2 and run for each race and ranks every split within the distance, overall and by division. Full and half results are ranked separately.
Frequently asked questions
What is T1 in triathlon?
T1 is the first transition, the time between leaving the swim and starting the bike. It includes running to the bike rack, removing the wetsuit and putting on a helmet and bike shoes.
What is T2 in triathlon?
T2 is the second transition, the time between finishing the bike and starting the run. You rack the bike, change into running shoes and head out.
What are the distances of a half-distance and full-distance triathlon?
A half-distance triathlon is a 1.9 km swim, 90 km bike and 21.1 km run. A full-distance triathlon is a 3.8 km swim, 180 km bike and a 42.2 km run.
Which triathlon split matters most for finish time?
In a 2025 study of 687,696 full-distance age-group finishes, bike and run times correlated more strongly with overall finish time than swim time did. The swim is the shortest leg of the race.
What is the average full-distance triathlon finish time?
In the same study, the mean age-group finish was about 12:20 for men aged 35 to 39 and about 13:20 for women aged 35 to 39, and times rose with age. Course and conditions change results a lot.