Pool Volume Calculator
Use this pool volume calculator to find how many gallons and liters of water a pool holds. Pick a rectangle, round, oval or kidney shape, enter the size and the shallow and deep end depths, and it averages the depth for you. It also gives cubic feet, cubic meters, the weight of the water and, if you enter a flow rate, how long the pool takes to fill. It does not give chemical doses. For the flow rate itself use the GPM calculator, for plumbing the pipe volume calculator and for any other volume the cubic yard calculator.
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US gallons
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Liters
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Volume (cu ft)
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Volume (m³)
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Surface area
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Average depth
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Weight of the water
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Time to fill at this flow rate
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Average depth = (shallow + deep) ÷ 2, which is exact only for a floor with a constant slope. Volume = surface area × average depth, with area = length × width for a rectangle, π ÷ 4 × length × width for an oval, π ÷ 4 × diameter² for a round pool and 0.45 × (A + B) × length for a kidney pool (the pool-industry rule of thumb, so kidney and free-form results are approximations). Gallons = cubic feet × 7.48052, and water weighs about 62.4 lb per cubic foot (8.34 lb per gallon). Chemical doses are not included: follow the product label for your measured volume.
GPM Calculator · Pipe Volume Calculator · Cubic Yard Calculator · Square Footage Calculator
More in this group
- Cubic Yard Calculator Length × width × depth to cu yd, cu ft, m³ and tons.
- Pipe Volume Calculator Gallons, liters and cubic feet a length of pipe holds.
- GPM Calculator Gallons per minute from volume and time or pipe size.
- Square Footage Calculator Area of a room or shape in sq ft, sq yd, sq in, and sq m.
How it works
- How do I calculate pool volume in gallons?
- For a rectangle multiply length × width × average depth in feet to get cubic feet, then multiply by 7.48 gallons per cubic foot. A 20 ft × 10 ft pool with an average depth of 5 ft is 1,000 cubic feet, or about 7,481 gallons. Many pool guides round the factor to 7.5.
- How do I find the average depth?
- Add the shallow end depth and the deep end depth and divide by 2. A pool that is 3 ft at one end and 8 ft at the other averages 5.5 ft. This is exact for a constant slope. If the floor has a flat shallow section and a steep drop, work out each part separately and add the volumes.
- What are the formulas for oval and kidney pools?
- Oval: π ÷ 4 × length × width × average depth × 7.48 (guides write 0.785 or 3.14 × 0.25). Kidney: 0.45 × (A + B) × length × average depth × 7.48, where A and B are the widest points of the two lobes. Round: π ÷ 4 × diameter² × depth × 7.48. Kidney and free-form results are approximations.
- How long does it take to fill a pool?
- Divide the gallons by the flow rate in gallons per minute, then divide by 60 for hours. 7,481 gallons at 10 gallons per minute is about 12.5 hours. Measure your real flow rate, for example by timing how long a 5-gallon bucket takes to fill, or use the GPM calculator.
- How much does the water in a pool weigh?
- Water weighs about 8.34 lb per US gallon, or 62.4 lb per cubic foot. A 7,481 gallon pool holds about 62,400 lb of water, which is roughly 31 US tons or 28 metric tonnes.