Swimming Speed Calculator

Calculator Inputs

Enter your swim details. Add strokes and weight for extra metrics.

Distance preset

Pick a preset or keep Custom.

Distance

Pool length

Stroke

Time (hours)

Time (minutes)

Time (seconds)

Strokes per length (optional)

Used for SWOLF, distance per stroke, and stroke rate.

Body weight (kg, optional)

Effort level (estimate)

Only used for calorie estimates if weight is provided.

Reset

Example Data

Use these sample inputs to test the calculator.

Distance	Pool	Time	Strokes/Length	Expected Pace	Notes
100 m	25 m	00:02:00	18	02:00 /100m	Good for steady aerobic sets.
400 m	50 m	00:08:20	22	02:05 /100m	Track long repeats and efficiency.
500 yd	25 yd	00:09:10	19	01:50 /100yd	Common benchmark in yard pools.

Formula Used

Total time (seconds): time = hours×3600 + minutes×60 + seconds
Speed: speed = distance ÷ time
Speed conversions: km/h = m/s × 3.6, mph = m/s × 2.23694
Pace per 100: pace₁₀₀ = time × (100 ÷ distance)
Lengths: lengths = distance ÷ pool length
Average length time: avg = time ÷ lengths
SWOLF: swolf = avg length time + strokes per length
Distance per stroke: dps = pool length ÷ strokes per length
Calories (estimate): kcal = MET × 3.5 × weight(kg) ÷ 200 × minutes

Units are normalized to meters for calculations, then displayed in multiple formats.

How to Use This Calculator

Enter distance and choose meters or yards.
Enter pool length and select its unit.
Fill in your total time using hours, minutes, seconds.
Optional: add strokes per length to estimate SWOLF.
Optional: add body weight and effort for calories.
Press Calculate to view results above the form.
Use CSV or PDF buttons to save results.
Repeat for different sets to compare pacing.

Tip: keep pool length correct for accurate lengths and SWOLF.

FAQs

1) What is pace and how is it different from speed?

Pace is the time needed to cover a fixed distance, like 100 meters. Speed is distance covered per second or hour. Coaches often prefer pace because it maps directly to set intervals and target splits.

2) Can I use this for yard pools?

Yes. Choose yards for distance and pool length when needed. The calculator converts internally and then shows pace for 100 yards and 100 meters to help you compare sessions across different pools.

3) Why do I need pool length?

Pool length lets the calculator estimate completed lengths and average time per length. That makes split planning easier and enables efficiency metrics like SWOLF when you provide strokes per length.

4) What does SWOLF mean?

SWOLF combines average time per length and strokes per length. Lower values usually indicate better efficiency, but compare only within similar strokes and pool lengths. It is most useful for tracking trends over weeks.

5) My lengths are not a whole number. Is that okay?

Yes. Open-water swims, mixed sets, or odd pool distances can create fractional lengths. The average time per length still helps estimate pacing, but SWOLF is best when lengths are consistent.

6) Are the calorie numbers accurate?

They are estimates based on effort and body weight. Technique, water conditions, and individual physiology change energy cost. Use the calorie output for rough tracking, not as a medical or nutrition prescription.

7) How can I improve my pace results?

Try consistent interval sets, controlled breathing, and better streamlining off the wall. Track SWOLF to see if you are moving faster with fewer strokes. Small technique gains can yield large pace improvements.

8) What should I export to keep a training log?

Export the CSV if you want easy spreadsheets and charts. Export the PDF when you need a clean shareable summary. Both formats include key pace, speed, and efficiency results from your latest calculation.