Calculate your triathlon or Ironman finish time from swim, bike, run and transition splits, or solve one split from a goal time, with pace and speed.
How the Triathlon Time Calculation Works
The finish-time mode adds five elapsed times: swim, first transition, bike, second transition, and run. Missing-split mode rearranges that same equation. It subtracts four known splits from the goal and rejects a zero or negative remainder.
Use h:mm:ss, m:ss, or decimal minutes. Each duration rounds to the nearest millisecond before addition or subtraction; integer milliseconds preserve the split arithmetic. Blank transition inputs mean zero, including when their optional section is closed. Pace and speed are derived afterward from the selected event distances, so changing a preset does not change the entered time total; it changes only the distance-dependent outputs.
| Preset | Swim | Bike | Run |
|---|---|---|---|
| Sprint | 750 m | 20 km | 5 km |
| Standard / Olympic | 1,500 m | 40 km | 10 km |
| IRONMAN 70.3 distance | 1.2 mi | 56 mi | 13.1 mi |
| Full distance | 2.4 mi | 112 mi | 26.2 mi |
Derived Pace and Speed
Swim pace divides the swim split by the number of 100-meter or 100-yard lengths in the course. Bike speed divides distance by hours. Run pace divides the run split by kilometers or miles. The result reports both common unit systems without asking the user to infer what a global measurement label means.
Worked Example
A standard-distance schedule of 30:00 swim, 3:00 T1, 1:20:00 bike, 2:00 T2, and 50:00 run totals 2:45:00. It corresponds to 2:00 per 100 m, 30 km/h on the bike, and 5:00 per kilometer on the run.
Using Missing-Split Mode
For a 5:30:00 goal with 40:00 swim, 5:00 T1, 4:00 T2, and 2:00:00 run, the remaining bike split is 2:41:00. If the known splits already equal or exceed the goal, no feasible missing split exists.
Assumptions and Limitations
The calculation adds or subtracts entered times at millisecond resolution; it is not a performance forecast. Generic race labels are planning references. Course-specific swim, bike, and run distances, timing-mat placement, transition layout, weather, elevation, and penalties can change the official result. Select Custom when the race information differs.
Sources
World Triathlon, Age-Group Racing. IRONMAN, 2026 Gulf Coast official event description and IRONMAN California official event announcement. Preset distances are nominal.
