About the Swimming Lap Calculator
Laps and lengths needed for a target swim distance in any pool size, with the time it will take.
Also known as: laps in a mile swimming, pool laps calculator, lengths for 1km.
How to use this calculator
- Enter target distance, pool length, pace per 100 m (mm:ss).
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
Lengths = distance ÷ pool length
Worked example
Using the values pre-filled in the calculator above:
- Target distance = 1,500 m
- Pool length: 25 m
- Pace per 100 m (mm:ss): 1:50
the calculator returns:
- Lengths: 60
- Laps (there and back): 30
- Estimated time: 0:27:30
- Distance per length: 25 m