Pool Volume Calculator

Calculate the water volume of a swimming pool in litres and gallons for rectangular, round and oval pools.

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How to Use This Calculator

How to Use

  1. Choose metric or imperial units.
  2. Select the pool shape.
  3. Enter the pool dimensions and the average water depth.

Average depth

If your pool has a shallow and a deep end, use the average of the two depths. For example, a pool that is 1 m at the shallow end and 2 m at the deep end has an average depth of 1.5 m.

Formulas

  • Rectangular: length × width × average depth
  • Round: π × radius² × average depth
  • Oval: π × (length ÷ 2) × (width ÷ 2) × average depth

Common Questions

How do I work out pool volume in gallons?

Calculate the volume in cubic metres, multiply by 1000 to get litres, then divide by 3.785 for US gallons or 4.546 for imperial gallons.

Why do I need to know my pool volume?

You need it to dose chemicals correctly, size a pump and heater, and estimate water and heating costs.

What is the average depth if my pool slopes?

Add the shallow-end depth and the deep-end depth and divide by two for a simple average.

How do I calculate the volume of my swimming pool?

Multiply the surface area by the average depth. The calculator handles rectangular, round and oval pools and converts to litres and gallons.

Why do I need to know my pool volume?

You need it to dose chemicals correctly and to size pumps, heaters and filters. Getting the volume right keeps the water safe and balanced.

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