Training / Swimming
Swim Pace Calculator: Pace per 100 m or 100 yd and Critical Swim Speed
Enter a distance and time to get your pace per 100 metres and per 100 yards, your speed, and how many lengths of a 25 m, 50 m, or 25 yd pool it is, and work out critical swim speed from a 400 and a 200 time trial.
Swim Pace Calculator: Pace per 100 m or 100 yd and Critical Swim Speed: Pace is time ÷ distance × 100: 1,500 m in 30 minutes is 2:00 per 100 m, or 1:50 per 100 yd, since a yard is 0.9144 m. In a 25 m pool that is 60 lengths at 30 seconds each. Critical swim speed is (400 time − 200 time) ÷ 2 per 100: 6:40 and 3:10 give 1:45 per 100. Runs 100% locally in your browser with zero server file uploads.
- Category
- Health & sport tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
Pace is the time for each 100 of your distance unit; yards are 0.9144 m, so the same swim is quicker per 100 yd. Critical swim speed, from a 400 and a 200 time trial in the same unit, is (400 time − 200 time) ÷ 2 per 100: roughly the fastest pace you can keep up for a long swim, and the usual base for threshold sets.
Doing the CSS test
After a warm-up, swim 400 as fast as you can, rest fully, then swim 200 all out, both in the same pool and stroke. Repeat the test every six to eight weeks to see whether your pace improves.
Triathlon
For the run leg, predict a race time from a recent result with the race time predictor.
How to use it
- Choose metres or yards and the pool length.
- Enter the distance and your time.
- Optionally add 400 and 200 time trials for your critical swim speed.
Privacy & limitations
Everything is calculated in your browser.
Related tools
Frequently asked questions
What is a good swim pace?
Many adult fitness swimmers swim 100 m in 2 to 2.5 minutes; club and triathlon swimmers often 1:30 to 1:50, and elite distance swimmers under 1:05.
What is critical swim speed?
An estimate of the fastest pace you can hold for a long swim without tiring quickly, from two maximal time trials; training sets are then given as CSS plus or minus a few seconds.
Do turns make a difference?
Yes: push-offs make short-course pools faster, so the same swimmer is a few seconds per 100 quicker in a 25 m pool than a 50 m pool.
Free tool · runs in your browser · no account required