Pool volume calculator

How it works

The calculator finds the surface area for your shape: length × width for a rectangle, π × radius² for a round pool, and π × half-length × half-width for an oval. It multiplies that by the average depth, the midpoint between shallow and deep ends, to get cubic feet. One cubic foot holds 7.48 US gallons.

Fill time is gallons divided by your hose’s flow rate. To measure the rate, time how long the hose takes to fill a 5-gallon bucket.

Example

With pool shape: rectangle, length 32 ft, width 16 ft, shallow end depth 3.5 ft, deep end depth 8 ft, fill rate 10 gal/min, the answer is 22,023 gallons.

Tips before you buy

• Measure to the water line, not the top of the wall. Above-ground pools are usually filled several inches below the rim.
• If the deep end is a short hopper rather than a steady slope, the simple average overstates the volume. Measure the sections separately.
• Chemical labels dose by gallons, so write your pool’s volume somewhere you’ll find it at the start of each season.

Common questions

How many gallons are in a cubic foot?

7.48 US gallons, or about 28.3 liters.

How many gallons is a 24-foot round above-ground pool?

At 4 feet of water, about 13,500 gallons. At 4.5 feet, about 15,200.

How long does it take to fill a pool with a garden hose?

At 10 gallons a minute, a 20,000-gallon pool takes about 33 hours.