Last updated: 3 October 2026
Reviewed by Jordan Morley, FA Level 2 Football Coach
SWOLF = strokes per length + seconds per length. A lower score means more efficient swimming. It combines two variables — how many strokes you take and how fast you cover the length. A swimmer can improve SWOLF by reducing strokes (better technique, longer reach, improved pull) or by going faster. In a 25m pool, SWOLF of 35 or below is excellent; 42 is good. Many GPS swim watches track SWOLF automatically. Swim Smooth uses SWOLF alongside CSS as a key training efficiency metric.
- Strokes + seconds per length
- Lower = more efficient
- 35 in 25m pool = excellent
- Improve via technique or speed
In practice
SWOLF (a swimming efficiency score combining stroke count and time for a set distance) rewards swimmers for covering distance using fewer, more powerful strokes rather than more frequent, weaker ones — a lower SWOLF score indicates better efficiency, and many swimmers track it over time as a proxy for technical improvement independent of raw speed, which can be affected by fitness changes rather than technique alone.
FAQ
How is SWOLF calculated?
Time taken (in seconds) to swim a set distance (commonly 25m or 50m), plus the number of strokes taken over that distance, combined into a single score — lower SWOLF indicates greater efficiency.
Why is SWOLF useful alongside raw swim speed?
Raw speed reflects both fitness and technique combined, while SWOLF isolates stroke efficiency more specifically, letting swimmers track technical improvement even during periods when fitness changes might otherwise mask it.