Pool Volume Calculator
Enter your pool's shape and average water depth to get its volume in litres or gallons. Knowing your volume is the first step to dosing chemicals correctly.
How pool volume is calculated
Volume is simply the surface area times the average water depth:
- Rectangular pool: length × width × average depth
- Round pool: π × radius² × average depth
Multiply cubic metres by 1,000 for litres. One cubic metre (m³) = 1,000 L ≈ 264 US gallons ≈ 220 UK gallons.
Frequently asked
- What is “average water depth”?
- Measure the water depth at the shallow end and the deep end and take the average. Use the water line, not the wall height — water usually sits below the rim.
- Litres or gallons?
- Use whatever your test kit and chemical labels use. Toggle the units above; the calculator converts for you (1 US gallon = 3.785 L, 1 UK gallon = 4.546 L).
- Why does pool volume matter?
- Every chemical dose is “per volume of water”. Get the volume wrong and every pH or chlorine dose after it is wrong too, which is how pools go cloudy or green.