Pool Health

Free pool tool

Pool Volume Calculator

Estimate how many gallons your pool holds. Pick the shape, enter the dimensions, and get the volume instantly — the number you need to dose chemicals and size equipment correctly.

Pool dimensions

All measurements in feet.

Shape
ft
ft
ft
ft

Estimated volume

21,065gallons

Based on an average depth of 5.5 ft. Use this to size chemical doses, heaters, and pumps.

Volume = surface area × average depth × 7.48 gallons per cubic foot. Irregular shapes and varying floor slopes will differ from this estimate.

Estimate only. Results assume a uniform shape and a linear floor slope. Pools with irregular shapes, attached spas, or varying depths will differ. For chemical dosing, confirm your volume and always follow product label directions.

How pool volume is calculated

Pool volume in gallons is the water-surface area times the average depth times 7.48 (the number of US gallons in a cubic foot).

  • Rectangle: length × width × average depth × 7.48
  • Round: π × (diameter ÷ 2)² × average depth × 7.48
  • Oval: (π ÷ 4) × length × width × average depth × 7.48

Average depth is the shallow-end depth plus the deep-end depth, divided by two. Knowing your exact volume matters: dose chemicals against the wrong number and you either waste product or fail to balance the water.

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