Pool Volume Calculator

Work out how many gallons and liters your pool holds from its shape, dimensions and depth, including pools with a shallow and a deep end.

Pool volume formulas

ShapeGallons
Rectanglelength × width × average depth × 7.48
Rounddiameter² × average depth × 5.87
Ovallength × width × average depth × 5.87

Average depth = (shallow end + deep end) ÷ 2. There are 7.48 gallons in one cubic foot, and 5.87 is 7.48 × π ÷ 4 for round and oval shapes.

Worked example

A 32 × 16 ft rectangular pool that is 3.5 ft deep at one end and 8 ft at the other has an average depth of 5.75 ft. Volume = 32 × 16 × 5.75 × 7.48 ≈ 22,000 gallons.

Why pool volume matters

  • Chemical dosing instructions are given per gallon of water.
  • Pump and filter sizing depends on turning over the full volume.
  • Heating cost depends on how much water you warm.

Results are estimates. Steps, slopes and freeform shapes change the true volume, so follow product labels and test your water regularly.

Frequently asked questions

How many gallons are in a 24-foot round pool?

At 4 ft average depth, about 13,500 gallons; at 4.5 ft, about 15,200 gallons.

How do I measure an irregular pool?

Split it into simple shapes, calculate each one and add them up.

How do I convert gallons to liters?

Multiply by 3.785.

Should I measure depth to the water line?

Yes. Measure to the actual water level, not the top of the wall.

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