One number for efficiency
SWOLF adds the seconds you take for one length to the number of strokes you use. Thirty-two seconds and eighteen strokes gives 50. Lower is better, because it means you covered the length in less time or with fewer strokes — ideally both. It is a crude metric, but it is measurable on every length without any equipment.
Why pool size must be stated
A 50 m pool doubles both terms, so a SWOLF of 90 in a long-course pool is roughly equivalent to 45 in a 25 m pool. The calculator normalises to 25 m so scores from different pools can be compared, but the raw score is what you track week to week in your own pool.
What to do with the score
If time is high and strokes are low, you are gliding too much or losing the catch. If strokes are high and time is low, you are rushing the stroke. The productive change is usually to cut two strokes per length while holding the same time — that is a real efficiency gain, and it will show up over 1500 m far more than a faster single length.
Frequently Asked Questions
What is a good SWOLF score?
In a 25 m pool: 30–35 advanced, 36–45 intermediate, 46–55 developing. Beginners often start above 55.
Does equipment change SWOLF?
Yes. Fins and paddles change both stroke count and speed, so compare like with like.
Should I measure every length?
No. Measure a representative length mid-set, when you are swimming normally rather than sprinting or recovering.
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