SWOLF Calculator - Swim Score, Watch vs Hand Count

SWOLF score from your time and stroke count

Thirty seconds for a length and fifteen strokes give a SWOLF of 45. That is the example in Garmin's own manual, and it is the whole formula: seconds plus strokes for one pool length, lower is better. The catch is the word "stroke". A Garmin counts one every time the arm with the watch finishes a full cycle, while the Topend Sports SWOLF test counts every hand entry, left and right together, so the same swim scores 60 by hand. This SWOLF calculator works out both, averages several lengths, adds pace per 100 yards or meters, distance per cycle and the stroke index, and checks whether a lower score on a second swim is real progress or just a longer glide.

Quick start. Swim 4 lengths at one steady effort, note the total time and the total strokes from your watch, and type them in with the pool length. One length works too, but a strong push-off or an uneven start can skew a single length.

From the pool deck to a SWOLF in five moves

1
Pool length - 25 yards, 25 meters, 50 meters, or another length in yards or meters (a hotel pool of 20 yards, a 33.33 m pool). Pace follows the pool: per 100 yards in a yard pool, per 100 meters in a meter pool.
2
How you count strokes - full cycles of one arm, the way a Garmin watch does, or every hand entry with both arms, the count the Topend Sports test uses. One cycle is two hand entries.
3
Number of lengths - how many lengths you swam at one effort without stopping. Empty means one.
4
Total time and total strokes - minutes and seconds for all those lengths together (seconds may be 28.4), and all the strokes counted the way you chose in step 2. The calculator divides both by the number of lengths.
5
A second swim (optional) - the time and strokes of another swim over the same lengths, for example after a drill set. The result then sets the two side by side and says which part of the score moved.

Watch count or hand count: two scores for one swim

Both sources agree on the sum. They disagree on what a stroke is, and that alone moves the score by the number of cycles in a length. The table puts the two definitions next to each other, with the example each source gives.

Source	One stroke is	Example given	Same swim, other count
Garmin manual	a full cycle of the arm wearing the watch	30 s + 15 strokes = 45	60 by hand entries
Topend Sports test	every hand entry, left and right combined	25 s + 20 strokes = 45 (50 m pool)	35 by cycles

The only benchmark in either source comes from Topend Sports and uses the hand-entry count: 35 to 45 over 25 meters is very good, and a score in the low 70s over 50 meters is excellent. A watch reading of 45 in a 25 m pool is therefore not "very good" by that yardstick until it is converted: 30 seconds and 15 cycles is 60 in hand entries.

Six swims, run through the calculator

The numbers from the watch manual

Input: 25 m pool, cycles, 1 length, 30 s, 15 strokes. Output: SWOLF 45, pace 2:00 per 100 m, 1.67 m per cycle, stroke index 1.39; by hand entries 60, above the 35 to 45 range.

100 yards counted in your head

Input: 25 yd pool, hand entries, 4 lengths, 1:40, 72 entries. Output: 25 s and 18 entries a length, SWOLF 43 (34 in cycles), pace 1:40 per 100 yd, 2.78 yd per cycle, stroke index 2.32. There is no yard-pool benchmark; scaled to 25 m by length it is about 47.

Long course, 100 m in 1:20

Input: 50 m pool, hand entries, 2 lengths, 1:20, 64 entries. Output: 40 s and 32 entries a length, SWOLF 72, in the low 70s, pace 1:20 per 100 m, stroke index 3.91.

A watch score of 70 in a 50 m pool

Input: 50 m pool, cycles, 4 lengths, 3:20, 80 cycles. Output: 50 s and 20 cycles a length, SWOLF 70. Counted in hand entries it is 90, well above the low 70s: the watch number only looks excellent.

A longer glide, a lower score, a slower swim

Input: 25 yd pool, cycles, 2 lengths; swim 1 1:00 and 34 cycles, swim 2 1:02 and 30 cycles. Output: SWOLF 47 to 46, but each length 1 s slower. The calculator flags it as fewer strokes bought with speed.

Better on both counts

Input: as above, swim 2 0:58 and 32 cycles. Output: SWOLF 47 to 45, one second and one cycle less per length. Only this kind of drop is clear progress: faster, with fewer strokes.

SWOLF chart for a 25-yard pool

Rows are seconds per 25-yard length, columns are full arm cycles per length, the way a watch counts. The last column is the 10-cycle score again in hand entries, the count the Topend Sports figures use.

Time per 25 yd	Pace per 100 yd	8 cycles	10 cycles	12 cycles	10 cycles = 20 entries
15 s	1:00	23	25	27	35
20 s	1:20	28	30	32	40
25 s	1:40	33	35	37	45
30 s	2:00	38	40	42	50
35 s	2:20	43	45	47	55
45 s	3:00	53	55	57	65

Two things stand out. A second and a cycle weigh the same in the score, although for a swimmer they cost very different things. And at 30 seconds a length nobody gets under 38 even with 8 cycles, so a low SWOLF needs speed first. This is also why there is no honest "SWOLF score chart by age": the number depends on pool, stroke, counting method and arm length long before age comes in.

Where the score misleads

Comparing watch and hand counts. A score of 45 from a Garmin and 45 from a friend counting entries are different swims; the second swimmer took half as many arm cycles per second spent.

Comparing pools. A 25 yd length is 22.86 m, so the same swimmer scores lower in a yard pool than in a 25 m pool. Scaling by length ignores the extra turns and push-offs in the shorter pool.

Comparing people. Swimmers differ in how far one cycle carries them, so SWOLF is a yardstick for your own swims in one pool, not a ranking.

Chasing the number with the glide. Two cycles fewer and one second slower still lowers the score. If the target is a faster 500, that is a step back, which is why the second-swim table shows time and strokes separately.

Distance per cycle and the stroke index

Distance per cycle is the pool length divided by the full arm cycles in it. In a study of 39 competitive swimmers, Costill and colleagues found it was the single best predictor of a 400-yard front crawl time, with a correlation of 0.88. The stroke index multiplies speed by distance per cycle; a conference paper on stroke index values (Sanchez and Arellano, ISBS) credits that definition to the same group and treats it as an indicator of efficiency. The calculator reports it in meters squared per second per cycle in every pool, so yard and meter swims compare. Because a whole length includes the push-off and glide, both numbers come out longer than the arms alone deliver.

SWOLF, asked by swimmers

What is a good SWOLF score?

The only published yardstick in the sources here is Topend Sports: 35 to 45 over 25 meters is very good, the low 70s over 50 meters is excellent, both counting every hand entry. For a watch score, double the cycles before comparing. More useful than any yardstick is your own trend in the same pool.

How do I calculate SWOLF by hand?

Time one length in seconds and count the strokes on that length, then add the two. For several lengths, add up the time and the strokes and divide each by the number of lengths first: 2:00 and 72 entries over 4 lengths gives 30 + 18 = 48.

Is a SWOLF of 40 good?

In a 25 m pool counted in hand entries, yes, it sits inside the 35 to 45 range. On a Garmin it is the equivalent of, for example, 25 seconds and 15 cycles, which is 55 in hand entries. In a 25 yd pool there is no published range to hold it against.

Does SWOLF work for breaststroke or open water?

The sum works for any stroke, but none of the sources gives separate ranges per stroke, so compare breaststroke only with breaststroke. In open water Garmin calculates swolf over 25 meters; this calculator needs pool lengths.

Why did my SWOLF drop while I got slower?

Because the score falls whenever you take one stroke fewer and lose less than one second. A longer glide does exactly that. Type both swims and the result says whether the drop came from time, strokes or both.

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