Pool Volume Calculator

Pick the pool shape — rectangle, round, or oval — enter the dimensions in feet, and get the water volume in gallons, liters, and cubic feet. For pools with a shallow and a deep end, the sloped mode averages the two depths, which is the standard approximation for a straight slope.

Volume is the number every chemical dose, pump sizing, and heater calculation starts from, so it's worth getting right once.

Common uses

• Dose chlorine and balancers correctly for your water volume
• Size a pump, filter, or heater for the pool
• Estimate the cost of filling a new pool

Example

Rectangle, 30 × 15 ft, depth 5 ft

16,830 gallons (2,250 ft³)

Limitations

• Uses 7.48 gallons per cubic foot and averaged depth — freeform shapes and steep drop-offs deviate from the estimate.

How do I calculate how many gallons my pool holds?

Multiply length × width × average depth in feet to get cubic feet, then multiply by 7.48 gallons per cubic foot. A 30 × 15 ft rectangle with 5 ft of water is 2,250 ft³, or about 16,830 gallons; round and oval pools use their area formulas instead.

How do I handle a pool with a shallow end and a deep end?

Average the two depths — (shallow + deep) ÷ 2 — and use that as the depth, which is the standard approximation for a straight, even slope. The sloped mode does this for you; pools where the bottom drops off suddenly hold a bit less than the estimate.

Do my pool measurements get sent anywhere?

No. The volume math runs locally in your browser — dimensions are never uploaded or stored, and the page works the same with the connection gone once loaded.

Why do I need to know my pool volume for chemicals?

Chemical doses are specified per volume of water — chlorine, for instance, is typically dosed per 10,000 gallons. Guessing the volume wrong means every dose is off by the same factor, so an accurate one-time volume figure keeps all your water chemistry honest.