Key Takeaways
- Pace per 100, finish times, critical swim speed (CSS), race predictions, stroke metrics and World Aquatics points, each tied to a published method with its limits stated.
- A swim of 1,500 m in 30:00 is 2:00.0 per 100 m. Distance ÷ time is all there is to it, and the Pace tab does it in yards as well.
- CSS comes from two maximal swims, the slope between them[2]. Your two times of 3:00 for 200 m and 6:30 for 400 m give 1:45.0 per 100 m.
- There are no SWOLF bands, age averages or open-water adjustments here, because none of them traces back to a published source. The last section lists what was left out.
How the Calculator Works
Five tabs, one method each, and the basis for it.
| Tab | How it is worked out | Basis |
|---|---|---|
| Pace and time | Distance, time and pace per 100 solved for whichever is missing | Arithmetic |
| Critical swim speed | The slope of distance against time between a shorter and a longer maximal swim | Wakayoshi et al.[1][2] |
| Race times | Your time × (new distance ÷ your distance) raised to a swimming exponent | Riegel 1981[3] |
| Stroke and SWOLF | Time plus strokes, stroke rate, distance per cycle, and speed × distance per cycle | Costill et al., Lätt et al.[4][14] |
| Points | 1,000 × (base time ÷ your time)³, rounded down, with the 2026 base times | World Aquatics[5] |
What each tab works out and where the method comes from. Source numbers match the sources list.
Your inputs stay in your browser. Each tab keeps its own, and nothing is sent anywhere.
How to Calculate Swimming Speed and Pace
Distance divided by time, shown per 100 because that is how pools are paced.
Speed is distance ÷ time. Pace per 100 is time ÷ distance × 100. Swimmers quote pace because it matches the pace clock on the wall, so a faster swimmer has the smaller number.
Worked example: 1,500 m in 30:00
1,800 seconds ÷ 1,500 m × 100 = 120 seconds, which is 2:00.0 per 100 m. In yards that is 1:49.7 per 100 yd, because 100 yd is 91.44 m.
Speed is 0.833 m/s, or 3.00 km/h. In a 25 m pool that is 60 lengths at 30.0 s each.
Turn it round to ask how far you get. At 2:00.0 per 100 m, 45 minutes gets you 2,250 m, which is 90 lengths of a 25 m pool.
The finish-time table on the Pace tab labels each row "if you could hold this pace". It is arithmetic, not a prediction, since pace slows as a swim gets longer. For a prediction, use the Race times tab.
Critical Swim Speed (CSS) and Threshold Pace
A pace you can test, retest and train from.
Wakayoshi and colleagues found that swim distance plotted against time is close to a straight line, and its slope is the critical velocity[2].
With a 200 m and a 400 m swim the slope is (400 − 200) ÷ (t400 − t200). In an eight-swimmer study it correlated with mean 400 m speed at r = 0.977[1].
Worked example: 3:00 for 200 m and 6:30 for 400 m
(400 − 200) ÷ (390 − 180) = 0.952 m/s, which is 1:45.0 per 100 m. A 1 s timing error on either swim moves that by about 0.50 s per 100, so time the two swims carefully.
The method has limits. The result shifts with the distances you pick, and CSS may not match the speed at which lactate stays steady[10]. A review of critical-speed work also warns that tests in a 25 m pool, a 50 m pool and open water are not interchangeable[7][10].
The page does not show D′, the distance you can swim above CSS. It was not reliable in a 2024 study of 32 national-level swimmers, though CSS from a 200 and 400 m pair was, with a coefficient of variation under 4% in all four strokes[8].
The training paces on the CSS tab are Swim Smooth's: easy at CSS + 8 to 10 s per 100, steady at CSS + 6 s, and threshold at CSS[6]. They are a coach's guideline, not research, and the tab says so.
Predicting Race Times: 400 m, 800 m and 1,500 m
Pace fades with distance, so the prediction is slower than your pace held flat.
Riegel fitted world records to the equation t = a·xb and, for swimming, found b = 1.02977 for men and 1.03256 for women, over the 400, 800 and 1,500 m events[3]. Because b is above 1, a longer swim takes more than proportionally more time.
Worked example: a 6:30 400 m, men's exponent
800 m: 390 × 21.02977 = 13:16, against 13:00 if you held pace. 1,500 m: 25:21, against 24:23.
Riegel's constants are checked in this page's tests against a published worked example[11]. The commonly quoted 1.06 is not his swimming value, so the calculator does not use it.
His data are world records up to 1979, so the exponent describes elite swimmers. There is no published exponent for recreational swimmers that I can cite, and the tab says so. Distances outside 400 to 1,500 m are hidden unless you ask for them.
What Is a Good or Average Swim Pace?
There is no published average for all swimmers, so here are the figures that can be traced.
No published average swim pace for the general public turned up, so age and level tables without a source can't be checked. Here are three anchors that can.
Trained swimmers. In a flume study of nine trained college swimmers, critical velocity averaged 1.166 m/s, ranging from 1.062 to 1.262 m/s[2]. That is 1:25.8 per 100 m on average, from 1:19.2 to 1:34.2. It is one small sample of trained swimmers, not a norm.
| Event | Men | Men /100 m | Women | Women /100 m |
|---|---|---|---|---|
| 100 m freestyle | 46.40 | 0:46.4 | 51.71 | 0:51.7 |
| 400 m freestyle | 3:39.96 | 0:55.0 | 3:54.18 | 0:58.5 |
| 1,500 m freestyle | 14:30.67 | 0:58.0 | 15:20.48 | 1:01.4 |
World Aquatics 2026 long course base times (1,000 points) as a pace per 100 m. These are world-record level, not targets.
The elite end. The table above is World Aquatics' world-record basis[5].
Your own age group. USA Swimming publishes motivational times (B to AAAA) for ages 10 and under through 17-18, in yards, short course metres and long course metres[13].
USA Swimming bases them on the 25th-fastest time in each event, gender and age group from the previous four-year period. That makes them a US age-group yardstick, not a world average. The Points tab shows where a swim sits against the world-record basis.
SWOLF, Stroke Rate and Distance Per Stroke
Measured from one timed length and a stroke count.
SWOLF is the time for a length in seconds plus the strokes you took. The same swim scores differently if you count every arm pull or only full cycles, so the calculator asks and shows both.
Stroke rate is cycles per minute. Distance per cycle is the length divided by cycles. Stroke index is speed × distance per cycle[14].
In a study of 25 adolescent boys swimming an all-out 100 m, stroke index was the best single predictor of the time[14]. That is one small sample, so treat it as a reason to track the number, not a target.
Worked example: 35 s and 36 arm pulls in a 25 m pool
SWOLF is 35 + 36 = 71, or 53 if you count cycles. That is 18 cycles per length, a stroke rate of 30.9 cycles per minute, and 1.39 m per cycle. Stroke index is 0.99.
There is no "good SWOLF" number here. No governing body publishes bands, and the bands on other sites disagree with each other.
The research is thin. One study of 188 university students tracked SWOLF from a 50 m sprint through a crawl course and called it a promising tool, with a lower score reflecting better technique, more speed, or both[9].
Compare it only with your own earlier swims, in the same pool, stroke and effort. Because the figures here come from a whole length, the push-off is included. Distance per cycle comes out higher, and stroke rate lower, than a mid-pool measurement would give.
World Aquatics Points
One scale for every stroke and distance.
World Aquatics scores a swim as 1,000 × (base time ÷ your time)³, rounded down[5]. The base time is set from the world record, so a world-record swim is worth about 1,000 points. Cubing the ratio means that a swim 10% slower than the base time scores about 751, not 900.
Worked example: men's 100 m freestyle in 1:00.00, long course
The base time is 46.40. (46.40 ÷ 60.00)³ × 1,000 = 462 points, and your speed is 77.3% of the base-time speed.
The page uses the 2026 base times for long and short course, men and women, checked against World Aquatics' official sheet. It publishes no yard table, so yard times are not scored.
The long course table covers 1 January to 31 December 2026, and the short course table runs from 1 September 2026 to 31 August 2027. World Aquatics resets them every year, so the same time can score differently next season.
Accuracy and Limits
What each number can and cannot tell you.
- Pace and time are exact arithmetic. They are only as good as the distance and the clock you entered.
- CSS shifts with the pair of distances you test and with the pool. Compare results only from the same pair and the same pool.
- Race predictions use an exponent fitted to world records up to 1979. Treat them as a guide to how pace fades, not as a race-day forecast.
- Stroke metrics depend on how you count strokes, and include the push-off.
- Points depend on the table year, and have no yard version.
- Nothing here accounts for turns, drafting, open-water conditions, a wetsuit, water temperature, or whether you swam the length flat out.
- This is an educational tool. It is not coaching or medical advice. If you are new to hard swimming or have a health condition, ask a coach or doctor before you test.
What Was Removed or Left Out
Earlier versions of this tool showed numbers that could not be traced to a source.
These are gone, or were never added, and the reason:
- The 1.06 exponent and the stroke-specific "adjustment factors". 1.06 is not one of Riegel's swimming fits, and nothing published backs the factors.
- Estimated stroke counts, "optimal" distance per stroke and SWOLF level bands. No source.
- Performance levels and averages by age. No source.
- Open-water and wetsuit adjustments. No source.
- Pool-course conversion. The one worked method that could be traced is a 2019 school statistics paper, which notes that USA Swimming has no official model[12].
- Points for yard pools. World Aquatics publishes none.
- A swimming VO2max estimate. No validated formula could be found.
For calories burned while swimming, use the swimming calories calculator. For a training-load score from a swim, use the Training Stress Score calculator.
Frequently Asked Questions
Sources & References
- Does critical swimming velocity represent exercise intensity at maximal lactate steady state?. Wakayoshi K, Yoshida T, Udo M, Harada T, Moritani T, Mutoh Y, Miyashita M. Eur J Appl Physiol 66(1):90-95 (1993)
- Determination and validity of critical velocity as an index of swimming performance in the competitive swimmer. Wakayoshi K, Ikuta K, Yoshida T, Udo M, Moritani T, Mutoh Y, Miyashita M. Eur J Appl Physiol 64(2):153-157 (1992)
- Athletic records and human endurance. Riegel PS. American Scientist 69(3):285-290 (1981)
- Energy expenditure during front crawl swimming: predicting success in middle-distance events. Costill DL, Kovaleski J, Porter D, Kirwan J, Fielding R, King D. Int J Sports Med 6(5):266-270 (1985)
- Swimming Points (formula and base-time tables). World Aquatics. worldaquatics.com
- Understanding Swim Training Zones (CSS-based zones, a coaching guideline). Swim Smooth. blog.swimsmooth.com
- An updated methodology to estimate critical velocity in front crawl swimming: a scoping review. Petrigna L, Karsten B, Delextrat A, Pajaujiene S, Mani D, Paoli A, Palma A, Bianco A. Science & Sports 37:373-382 (2022)
- Stroke-specific swimming critical speed testing: balancing feasibility and scientific rigour. Scott BE, Burden R, Dekerle J. J Hum Kinet, 239-251 (2024)
- Assessment and prediction of swimming performance using the SWOLF index (188 university students, 50 m sprint test). Madou T, Vanluyten K, Martens J, Iserbyt P. Int J Kinesiology in Higher Education 7:76-85 (2021)
- Swimming: critical speed (secondary source, summarises the Dekerle findings on lactate steady state). AgonCalc. agoncalc.it
- Course notes, example problems (secondary source, Riegel's swimming constants in a worked example). Johnson A, University of Maryland ENBE 415. artjohnson.umd.edu
- Course conversion (a 2019 school statistics project, not peer-reviewed; notes USA Swimming has no official model). Vercruysse A. Menlo School
- 2024-2028 Motivational Standards, age group (the method is described on USA Swimming's times page). USA Swimming. usaswimming.org
- Physiological, biomechanical and anthropometrical predictors of sprint swimming performance in adolescent swimmers. Lätt E, Jürimäe J, Mäestu J, Purge P, Rämson R, Haljaste K, Keskinen KL, Rodriguez FA, Jürimäe T. J Sports Sci Med 9:398-404 (2010)
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Disclaimer: This calculator is for informational and personal journaling purposes only. It logs measurements and compares them to published reference values. It is not health, medical, or nutrition advice.