Swim Pace Calculator
3.8 km in 1 hour is a pace of 1:35 per 100 m
Swimming 3.8 km in 1 hour requires a pace of 1:35 per 100 m (15:50 per km / 25:29 per mile). This distance is the Full Ironman swim (3.8 km).
At 1:35/100 m, each 25 m lap takes 0:24 and each 50 m length takes 0:48. To check a different time for 3.8 km, or to explore pool and open-water splits, use the calculator below.
Pace breakdown
| Distance | 3.8 km |
| Target time | 1 hour |
| Pace per 100 m | 1:35 |
| Pace per km | 15:50 |
| Pace per mile | 25:29 |
Training paces at 1:35/100 m
Derived from your 1:35/100 m race pace using the same formula as the Swim Pace Calculator.
| Easy (warm-up / recovery) | 1:49/100 m |
| Aerobic base | 1:40/100 m |
| Threshold | 1:30/100 m |
| Build sets | 1:26/100 m |
| Sprint intervals | 1:21/100 m |
| Lap pace (25 m pool) | 0:24/lap |
Try a different time for 3.8 km
- 3.8 km in 50 minutes = 1:19/100 m
- 3.8 km in 55 minutes = 1:27/100 m
- 3.8 km in 1 hour = 1:35/100 m
- 3.8 km in 1 hr 5 min = 1:43/100 m
- 3.8 km in 1 hr 10 min = 1:51/100 m
- 3.8 km in 1 hr 15 min = 1:58/100 m
- 3.8 km in 1 hr 20 min = 2:06/100 m
- 3.8 km in 1 hr 25 min = 2:14/100 m
- More times available above and below
Want to calculate a different pairing? Open the Swim Pace Calculator to enter any distance and time, see pool and open-water splits, and build your training zones.