Pool Lap Calculator
Converts a swimming distance into lengths or laps for a 25m or 50m pool.
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Result
Fill in the fields to see your result.
Estimate only — real results depend on terrain, weather, fatigue, conditions and individual fitness. Not medical or coaching advice.
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter your pool length and the target distance.
- Read the number of lengths and laps.
How it works
Lengths = distance ÷ pool length. A lap is two lengths (down and back).
Worked example
1500 m in a 25 m pool. = 60 lengths (30 laps).
Common mistakes
- Confusing a lap with a length — many pools count one length as a lap, so check which your event uses.
- Using the wrong pool length — a 25 m and a 50 m pool need very different lap counts.
Tips
- Times are estimates only — not medical or coaching advice. Always train safely and follow event rules.
- Distances are editable: choose “Custom…” to enter your own course lengths.
Frequently asked questions
How many laps is a kilometre?
In a 25 m pool 1 km is 40 lengths; in a 50 m pool it is 20 lengths. Enter your pool length to be sure.
Is a lap one length or two?
It varies by venue. In competition a lap usually means one length, but some clubs count there-and-back as a lap — the tool lets you set this.
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Cite this tool
Zerdly. (2026). Pool Lap Calculator. Retrieved from https://www.zerdly.com/tools/pool-lap-calculator/
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.