Swimming Pace Calculator
Enter any two fields (distance, time, pace per 100m) to calculate the third
| Distance | Estimated time | Lengths |
|---|---|---|
| 50m | 00:55 | 1.0 |
| 100m | 01:50 | 2.0 |
| 200m | 03:40 | 4.0 |
| 400m | 07:20 | 8.0 |
| 800m | 14:40 | 16.0 |
| 1500m | 27:30 | 30.0 |
- Work backward from a familiar distance: choose 400m and enter your finish time to get pace per 100m.
- Plan a goal time: choose the distance and enter the target time to see the required average pace.
- Want your real threshold speed instead of a single-swim estimate? Take two time trials at CSS Critical Swim Speed Test.
- Need race splits for each segment? Go to Swim Race Pace Planner.
Sprints (50m) and endurance swims (1500m) draw on different energy systems, so a single linear pace prediction gets less accurate the further apart the distances are. These two models explain why and offer a more precise alternative.
Riegel (1981) found that endurance performance follows T₂=T₁×(D₂/D₁)^1.06 rather than a simple linear ratio — the 1.06 exponent (not 1.0) reflects that longer distances slow disproportionately as energy systems shift. Originally validated in running, it also applies to swimming and cycling for quick cross-distance estimates.
Wakayoshi et al. (1992) validated that the speed derived from two maximal-effort time trials at different distances (e.g. 200m and 400m) correlates strongly with the physiological lactate threshold — a much better reflection of your current fitness than extrapolating from a single swim.
Sources: Wakayoshi et al. 1992, Eur J Appl Physiol, Riegel 1981, American Scientist