Pool Volume Calculator

Enter your pool's shape and dimensions to get gallons (and liters) — the one number every chemical dose, heater, and pump size depends on.

Inputs
ft ×
ft
ft
ft
Results update as you type — no submit
ResultsLIVE
Pool volume
21,065 gal
≈ 79,740 L
Surface area512 sq ft (47.6 m²)
Average depth5.5 ft (1.68 m)
Formula
surface = 512 sq ft · avg depth = 5.5 ft
volume = 512 × 5.5 × 7.48 = 21,065 gal (79,740 L)
Diagram — pool planNTS
L 32 ft16 ftAVG 5.5 ftPLAN · SURFACE = L × WMEASURESHEDRECTANGLE POOL21,065 GAL
Estimates for planning only — verify sizes and equipment before buying. For chemicals, always follow the product label, add chemicals to water (never the reverse), and test with a kit.
MeasureShedmeasureshed.com/calculator/pool-volume-calculator
Pool volume — summaryUNITS: FT · SCALE: NTS
Inputs
ShapeRectangle
Length × width32 × 16 ft
Depth (shallow → deep)3 → 8 ft
Results
Volume21,065 gal
Other units79,740 L
Surface area512 sq ft
Average depth5.5 ft
Pool planNTS
L 32 ft16 ftAVG 5.5 ftPLAN · SURFACE = L × WMEASURESHEDRECTANGLE POOL21,065 GAL
Shopping list
☐ Pool holds 21,065 gal — use for chemical dosing
Formula
volume = 512 sq ft × 5.5 ft × 7.48 = 21,065 gal
Estimates for planning only — verify sizes and equipment before buying. For chemicals, always follow the product label, add chemicals to water (never the reverse), and test with a kit.SHEET 1 OF 1
How it works

Every pool is a surface area multiplied by an average depth. The calculator finds the surface area from the shape you pick — a rectangle is `length × width`, a round pool is `π × radius²`, an oval is `π × (length/2) × (width/2)`, and a kidney is estimated as `0.45 × (widthA + widthB) × length` from the published pool-industry formula. It then multiplies by the average depth and converts cubic feet to gallons at `7.48` gallons per cubic foot.

Average depth is where most pool estimates go wrong. If the floor slopes from a shallow end to a deep end, the average is simply `(shallow + deep) ÷ 2` — a `3 ft` to `8 ft` slope averages `5.5 ft`, not `8 ft`. Using the deep-end number alone can overstate volume by half and wreck every chemical dose that follows.

The tool computes in liters internally and shows both US gallons and liters, because gallons is the number every other pool tool needs: chlorine, salt, alkalinity, heater sizing, and pump turnover all scale directly with volume. Get this number right first and the rest of the pool math falls into place.

Worked example
Rectangle `32 ft × 16 ft`, shallow `3 ft`, deep `8 ft`
average depth = (3 + 8) ÷ 2 = `5.5 ft`
volume = 32 × 16 × 5.5 = `2,816 cu ft`
gallons = 2,816 × 7.48 = `21,064 gal` (`79,700 L`)
Questions about pool volume
Measure length, width, and both the shallow and deep depths, then pick your shape. For a rectangle it is length × width × average depth × 7.48. A 32 × 16 ft pool averaging 5.5 ft holds about 21,000 gal. Round and oval pools use the circle/ellipse area instead of length × width.
SOURCES — Pentair / In The Swim pool-volume charts · 7.48 gal per cu ft (231 in³/gal)
Estimates for planning only — verify sizes and equipment before buying. For chemicals, always follow the product label, add chemicals to water (never the reverse), and test with a kit.
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