Find your swim pace per 100 m and per 100 yd, total time, pool-length count and SWOLF efficiency score from a distance and time or a single split.
A swim-training aid, not medical advice. SWOLF is only comparable within the same pool length.
About this tool
The Swim Pace & SWOLF Calculator turns a swim distance and time — or a single split — into your pace per 100 metres and per 100 yards, plus a SWOLF efficiency score. Everything runs in your browser and nothing is uploaded.
The core is the pace triangle: for a total distance D and total time T, pace per 100 = T ÷ (D ÷ 100). If you instead enter one split S over a length L, the total time is estimated as T = S × (D ÷ L). Distances convert with 1 yard = 0.9144 m, so metres and yards paces are always shown side by side (100 m ≈ 109.36 yd). The pool-length count is total distance ÷ pool length, with 25 m, 50 m and 25 yd pools selectable.
SWOLF ("swim golf") adds your stroke count for one length to the seconds for that same length — a lower number means more efficient swimming. Because both terms depend on how long the pool is, SWOLF is only comparable within the same pool length. Enter strokes and seconds per length to see it. This is a training aid, not medical advice.
Frequently asked questions
How is pace per 100 calculated?
Pace per 100 = total time ÷ (distance ÷ 100). Swimming 1500 m in 30:00 is 1800 s ÷ 15 = 120 s = 2:00 per 100 m. The per-100-yard value uses the same time over the distance expressed in yards.
What is SWOLF and why does the pool matter?
SWOLF is the strokes taken in one pool length plus the seconds for that length. Lower is more efficient. Since a 50 m length needs more strokes and time than a 25 m one, SWOLF scores are only comparable within the same pool length.
Can I work from a split instead of a full time?
Yes. Switch to split mode and enter the time for one interval (say 1:40 for 100 m) and your total distance. The tool scales that split across the whole distance to estimate total time and pace, assuming an even effort.
How do metres and yards relate?
One yard is 0.9144 m, so 100 m equals about 109.36 yd. A per-100 m pace is therefore always slightly slower-looking than the same effort per 100 yd, and the tool shows both from whichever unit you enter.