Swim lap calculator
Convert swim laps to distance or calculate pool lengths for a distance goal. Choose your pool length and count single lengths or round trips.
Results
Enter your values or try the example.
How it works
Distance = pool length × lengths. A round trip is two lengths. Fractional counts are shown exactly; the full-length target rounds up to reach at least your distance. Pool length and distance use the selected unit.
Set your counting convention
Choose whether you want a distance from a count or a count from a distance. Enter the actual pool length, then choose single lengths or round trips. One length is a crossing from one end to the other. One round trip returns you to your starting end, so it covers twice the pool length.
Example: 1,000 m in a 25 m pool
A 1,000 metre target requires 40 single lengths or 20 round trips in a 25 metre pool. In a 50 metre pool, the same target requires 20 single lengths. The distance unit applies to both the pool and your target; do not enter a pool length in yards while leaving metres selected.
When the target ends between walls
For 1,000 metres in a 33 metre pool, the exact count is about 30.30 lengths. Completing 31 full lengths reaches 1,023 metres, exceeding the goal by 23 metres. Use the full-length result when you want to finish at a wall. The calculator converts your inputs; it does not detect missed lengths or verify a distance recorded by a watch.