Swim Pace Calculator
Convert a swim distance and time into pace per 100 m and per 100 yd, speed, length count, stroke count and SWOLF — with exact yard-metre conversion.
Swim Pace Calculator: with the default inputs, pace is 1:40.0 / 100 m.
Sets the length count and whether the headline pace is per 100 m or per 100 yd.
Per 100 in the units of the pool you selected.
- Pace per 100 m
- 1:40.0 / 100 m
- Pace per 100 yd
- 1:31.4 / 100 yd
- Seconds per 100 m
- 100
- Average speed
- 1 m/s
- Pool lengths
- 60
- Seconds per length
- 25
- Estimated total strokes
- 800
- Strokes per length
- 13.3
- SWOLF score
- 38.3Seconds per length plus strokes per length. Lower is more efficient.
Assumptions
- Pace is a straight average over the whole swim — no allowance for negative or positive splits.
- Length count rounds to the nearest whole length when the distance is not an exact multiple of the pool.
- Stroke count is stroke rate × elapsed time, so it includes turns and any rest; it is a cadence estimate, not a count.
- SWOLF is seconds per length plus strokes per length and is only comparable within one pool length.
| Distance | Metres | Time | Pace / 100 m |
|---|---|---|---|
| 50 | 50 | 0:50 | 1:40.0 |
| 100 | 100 | 1:40 | 1:40.0 |
| 200 | 200 | 3:20 | 1:40.0 |
| 400 | 400 | 6:40 | 1:40.0 |
| 500 yd | 457.2 | 7:37 | 1:40.0 |
| 800 | 800 | 13:20 | 1:40.0 |
| 1000 | 1,000 | 16:40 | 1:40.0 |
| 1650 yd (mile) | 1,508.8 | 25:09 | 1:40.0 |
| 1500 | 1,500 | 25:00 | 1:40.0 |
| 1 mile open water | 1,609.3 | 26:49 | 1:40.0 |
Held at a constant pace — in practice long swims are slower per 100 than short ones.
How this is worked out
The formula
Pace per 100 m = total time ÷ (distance in metres ÷ 100) Pace per 100 yd = pace per 100 m × 0.9144 (1 yd = 0.9144 m exactly, so 100 yd = 91.44 m) Speed = distance ÷ time Lengths = distance ÷ pool length SWOLF = seconds per length + strokes per length Total strokes ≈ stroke rate (per minute) × time in minutes
Open How it’s calculated above to see this worked through with your own numbers.
What you enter
- Distance swum
- A number.in m, yd, km, mi · from 1 to 100000 · defaults to 1500
- Time — hours
- A number.from 0 to 24 · whole numbers only · defaults to 0
- Minutes
- A number.from 0 to 59 · whole numbers only · defaults to 25
- Seconds
- A number.from 0 to 59 · whole numbers only · defaults to 0
- Pool length
- Sets the length count and whether the headline pace is per 100 m or per 100 yd.25 m (short course metres) · 50 m (long course, Olympic) · 25 yd (short course yards) · 33⅓ m
- Stroke rate(under More options)
- Full stroke cycles counted as single arm pulls. Leave at 0 to skip the stroke estimate.from 0 to 120 · defaults to 32
What you get back
- Pacemain answer
- Per 100 in the units of the pool you selected.
- Pace per 100 m
- Pace per 100 yd
- Seconds per 100 m
- Average speed
- Pool lengths
- Seconds per length
- Estimated total strokes
- Strokes per length
- SWOLF score
- Seconds per length plus strokes per length. Lower is more efficient.
What this assumes
- Pace is a straight average over the whole swim — no allowance for negative or positive splits.
- Length count rounds to the nearest whole length when the distance is not an exact multiple of the pool.
- Stroke count is stroke rate × elapsed time, so it includes turns and any rest; it is a cadence estimate, not a count.
- SWOLF is seconds per length plus strokes per length and is only comparable within one pool length.
About this calculator
Swimming is measured in seconds per 100, and the unit of that hundred depends on which country's pool you are standing in. This calculator takes any distance and time and returns both — pace per 100 metres and pace per 100 yards — plus speed, length count, stroke estimate and SWOLF.
Yards and metres, done exactly
A yard is 0.9144 metres by international definition, so 100 yards is 91.44 metres — 8.56% shorter than 100 metres. That is why a 1:30 per 100 yd pace is a 1:38.4 per 100 m pace for the same swimmer at the same effort. The conversion here uses the exact factor, not the 0.914 approximation that leaves you a second out over a mile.
The distances themselves differ too. The "mile" in a yards pool is 1650 yards (1,508.8 m), the metric mile is 1500 m, and an open-water mile is the real 1,609.344 m. They are three different races and the calculator lists all three.
Reading the results
Pace is the headline, expressed in the units of the pool you selected. Seconds per length is the number to swim to on a pace clock. Speed in m/s is the one to use if you are comparing with an open-water GPS track, which reports speed rather than pace.
SWOLF — swim golf — adds the seconds for a length to the strokes taken on it. It is a crude but useful efficiency score: two swimmers can complete a length in the same time, one with 14 strokes and one with 22, and the first is doing it far more cheaply. Lower is better, and a typical adult freestyle SWOLF in a 25 m pool sits around 35–45. Compare it only against your own previous scores in the same pool, because the number scales with pool length and cannot be compared across 25 m and 50 m.
What limits the accuracy
The stroke count comes from a stroke rate you supply multiplied by elapsed time, so it includes turns, walls and any rest — it is an estimate of cadence, not a count. Short-course times flatter you: every turn is a push-off worth roughly half a second, so a 25 m pool is about 1–2 seconds per 100 m quicker than a 50 m pool for identical fitness, and yards pools quicker still.
Finally, the split table assumes you hold this pace at every distance, which nobody does. A swimmer's 100 pace is far quicker than their 1500 pace — expect a genuine 1500 to run several seconds per 100 slower than a fresh 100, and use the table as a target set rather than a prediction.
Frequently asked questions
▸How do I calculate swim pace per 100 m?
Divide your total time by the distance in hundreds of metres. 1500 m in 25:00 is 1500 seconds ÷ 15 = 100 seconds, a 1:40 per 100 m pace.
▸How do I convert 100 yard pace to 100 metre pace?
Multiply by 1.0936 — or divide the metre pace by that to go the other way. 100 yards is 91.44 m exactly, so a 1:30/100 yd pace is 1:38.4/100 m.
▸What is a good SWOLF score?
In a 25 m pool, most adult freestyle swimmers land between 35 and 45, and competitive swimmers below 30. Only compare it against your own scores in the same pool length — it is not comparable across pools.
▸How many lengths is a mile?
It depends on the pool and which mile. The yards "mile" is 1650 yd (66 lengths of 25 yd), the metric mile is 1500 m (60 lengths of 25 m), and a true mile is 1,609.344 m.
▸Why are short course times faster?
More walls means more push-offs, and an underwater push-off is faster than swimming. Expect roughly 1–2 seconds per 100 m between a 25 m and a 50 m pool at the same fitness.
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