Triathlon Split Time Estimator

Enter your target total race time and select a race format (Sprint, Olympic, Half-Ironman, or Ironman). The calculator distributes your target time across the swim, bike, and run segments using typical effort proportions for each discipline, then subtracts your transition times. You can also override individual paces or speeds to generate a custom split plan.

The estimator covers all four major triathlon formats: Sprint (750m/20km/5km), Olympic (1.5km/40km/10km), Half-Ironman / 70.3 (1.9km/90km/21km), and Ironman / 140.6 (3.8km/180km/42.2km). You can also enter fully custom swim, bike, and run distances to match any non-standard race.

For most triathletes, the swim accounts for roughly 10–15% of total race time, the bike 45–55%, and the run 30–40%, with transitions making up a small remainder. These proportions shift slightly with race length — at Ironman distances the run becomes a larger time chunk due to fatigue-related pace drops.

Enter your swim pace in minutes per 100 metres. The calculator multiplies this pace by the total swim distance (in 100m units) to produce your expected swim split. For example, a 2:00/100m pace over a 1,500m Olympic swim gives a swim split of approximately 30 minutes.

T1 (swim-to-bike) typically runs 2–5 minutes for most athletes depending on wetsuit use and racking distance. T2 (bike-to-run) is usually 1–3 minutes. At longer distances like Ironman, athletes sometimes spend more time in transitions to change clothes or eat. Input your realistic estimates to get an accurate projected finish time.

For a Half-Ironman (90km bike), beginner times range from 3:00–3:45, intermediate from 2:30–3:00, and advanced athletes from 2:00–2:30. For a full Ironman (180km bike), expect roughly 5:30–7:00 for beginners, 4:45–5:30 for intermediate, and under 4:30 for advanced riders.

Yes. Select 'Custom Distance' from the race format dropdown and enter your exact swim, bike, and run distances. The estimator will apply your specified paces or speeds (or auto-distribute from your target time) to those custom distances.

When no individual pace is entered, the calculator auto-distributes your target time across segments using fixed proportion weights (swim ~12%, bike ~50%, run ~36%, minus transitions). Changing the target time scales all splits proportionally. Entering a specific pace for any segment pins that split and the remaining time is redistributed.