Pool Volume Calculator
Pick your pool shape, enter the size and the depth at the shallow and deep ends, and the calculator returns the water it holds in gallons (plus litres and cubic feet). Knowing the gallons is the first step for dosing chlorine and other chemicals, sizing a heater or pump, and estimating fill time.
Your measurements
Rectangle and oval use length × width; round uses the diameter.
The longer side of the pool, at the waterline.
The shorter side of the pool, at the waterline.
Water depth at the shallow end. For a flat-bottom pool, set both depths the same.
Water depth at the deep end. Measure to the waterline, not the wall top.
Pool volume
21,065 gal
79,740 L · 2,816 ft³ · 32 × 16 ft
Estimates only. Verify against your supplier's coverage figures before ordering.
Footprint
Footprint to scale
The water
- Surface area
- 512 ft²
- Average depth
- 5.5 ft(3–8 ft)
- Cubic feet
- 2,816 ft³
- Litres
- 79,740 L
- Fill time
- 39 hr(at 9 gpm)
Length × width.
Halfway between the shallow and deep ends.
Surface area × average depth.
1 US gallon ≈ 3.785 litres.
Rough — well water and pressure vary; municipal fill may be metered.
The formula
Gallons = surface area × average depth (ft) × 7.48 · Rect area = L × W · Round area = π(d ÷ 2)² · Oval area = π(L ÷ 2)(W ÷ 2) · Avg depth = (shallow + deep) ÷ 2
Example: A 32 × 16 ft rectangular pool that slopes from 3 ft to 8 ft (5.5 ft average) holds 32 × 16 × 5.5 × 7.48 ≈ 21,000 gallons.
How it works
- 1Find the surface area: length × width for a rectangle, π × (diameter ÷ 2)² for a round pool, or π × half-length × half-width for an oval.
- 2Average the depth: add the shallow and deep depths and divide by two. A flat-bottom pool just uses its one depth.
- 3Multiply area × average depth for the volume in cubic feet.
- 4Multiply cubic feet by 7.48 to get US gallons (or by 28.3 for litres).
Frequently asked questions
How many gallons is my pool?
Multiply the surface area by the average depth (in feet), then by 7.48. A 32 × 16 ft pool averaging 5.5 ft deep holds about 21,000 gallons. Round pools use π × radius² for the area.
How do I find the average depth of a pool?
Add the shallow-end and deep-end depths and divide by two. A pool that goes from 3 ft to 8 ft has an average depth of 5.5 ft. A flat-bottom above-ground pool uses its single depth.
How many gallons in a 24-foot round pool?
A 24 ft round pool 4.5 ft deep holds about 15,200 gallons (π × 12² × 4.5 × 7.48). Above-ground pools are filled a few inches below the top rail, so the real number is slightly lower.
How long does it take to fill a pool?
A garden hose runs about 9 gallons per minute, so a 21,000-gallon pool takes roughly 39 hours. Two hoses or a larger supply line cut that down. The calculator estimates fill time from the rate you enter.