Work out your swim pace per 100 m or 100 yards
This swim pace calculator converts a swim distance and time into pace per 100 metres and per 100 yards, turns a target pace into a finish time, and works out your critical swim speed (CSS) from a 400 and a 200 time trial. It then lists projected times for common pool distances and for open-water triathlon swims, including the 1,900 m swim in a half-distance (70.3) race.
Swimmers and coaches in the UK, Australia and Europe think in metres; many US pools and school teams use yards. The tool shows both, using the exact conversion of 100 yd = 91.44 m. For running and cycling equivalents see the pace calculator and the cycling power zones calculator.
How to use the Swim Pace Calculator
- Choose Pace from time, Time from pace or CSS test, and the pool unit (metres or yards).
- For pace, enter the distance and your time (for example 1900 and 40:00). For a finish time, enter the distance and your pace per 100.
- For CSS, enter the times of an all-out 400 and an all-out 200 swum in the same session after a warm-up.
- Read the pace per 100 m and per 100 yd, the speed, and the table of projected times.
Swim Pace Calculator features
Metres and yards
Pace is shown per 100 m and per 100 yd at once, so a yard-pool set and a metre-pool race can be compared directly.
Critical swim speed
Uses the two-trial formula (400 − 200) ÷ (T400 − T200) to give a threshold-style training pace.
Triathlon swim times
Projected times for 750 m, 1,500 m, 1,900 m and 3,800 m at the pace you enter.
Flexible time entry
Type 40:00, 1:12:30, 95.5 or plain seconds; invalid times are explained, not guessed.
Speed too
Metres per second and kilometres per hour for comparing with running or cycling.
How the calculations work
Pace per 100 = time ÷ distance × 100. Swimming 1,900 m in 40 minutes is 2,400 s ÷ 1,900 × 100 = 126.3 s, or 2:06 per 100 m. Because a yard is shorter than a metre, the same effort is faster per 100 yd: 126.3 × 0.9144 = 115.5 s, about 1:56 per 100 yd.
Critical swim speed is the slope of the line joining your 200 and 400 results on a distance-time graph: CSS = (400 − 200) ÷ (T400 − T200). With a 6:00 400 and a 2:50 200 you cover 200 more units in 190 more seconds, 1.053 per second, a pace of 1:35 per 100. The method comes from the critical-velocity work of Wakayoshi and colleagues (European Journal of Applied Physiology, 1992), who found it tracked the speed at which blood lactate begins to accumulate in competitive swimmers.
| Race swim | Distance | Time at 2:00 per 100 m |
|---|---|---|
| Sprint triathlon | 750 m | 15:00 |
| Olympic triathlon | 1,500 m | 30:00 |
| Half distance (70.3) | 1,900 m | 38:00 |
| Full distance | 3,800 m | 1:16:00 |
Doing a CSS test well
Warm up for 10 to 15 minutes, swim the 200 first as hard as you can pace evenly, rest until you have fully recovered (at least 10 minutes of easy swimming or rest), then swim the 400. Use a push start, the same stroke and the same pool length for both. If the 400 is not at least 1.6 times as slow as the 200, one of the efforts was probably not maximal and the tool says so.
CSS is a pacing reference, and it differs from a race prediction. Open-water swims have wetsuits, currents and sighting, so treat the open-water table as an approximation. This calculator gives general training information, not coaching or medical advice.
Swim Pace Calculator FAQ
How do I calculate swim pace per 100 m?
Divide your time in seconds by the distance in metres and multiply by 100. For 750 m in 15:00, 900 ÷ 750 × 100 = 120 s, or 2:00 per 100 m.
What is a good swim pace for a 70.3 triathlon?
It depends on your level. Many age-groupers swim the 1,900 m in 35 to 50 minutes, which is roughly 1:50 to 2:35 per 100 m. Enter your target finish time to see the pace you need.
How do I convert pace per 100 yards to per 100 metres?
Divide the yard pace by 0.9144. A 1:30 per 100 yd pace is 90 ÷ 0.9144 = 98.4 s, or 1:38 per 100 m. The tool does this for you.
What is critical swim speed (CSS)?
The speed you could theoretically hold for a very long time without exhaustion, estimated from a 400 and a 200 time trial. Coaches use its pace for threshold sets.
Should my CSS trials be in a 25 m or 50 m pool?
Either, as long as both trials use the same pool. Turns help, so a short-course CSS is usually a little faster than a long-course one.
Can I use it for open-water swimming?
Yes for planning, using a pace from the pool. Expect open-water times to be slower or faster depending on wetsuit, current and navigation.