Pool volume calculator
How many gallons of water your pool holds, in-ground or above-ground, with how long it takes to fill and what the water costs.
Your pool holds about
22,023 gallons
- Liters
- 83,365 L
- Cubic feet
- 2,944.0 cu ft
- Cubic meters
- 83.36 m³
- Water surface
- 512.0 sq ft
- Average depth
- 5.75 ft
- Time to fill
- Water cost
US gallons, for water filled to the depths you enter. A pool that doesn't slope evenly from end to end holds somewhat more or less.
How to calculate pool gallons
Find the water's surface area, multiply by the average depth for cubic feet, then convert: each cubic foot holds 7.48 US gallons.
- Surface area: rectangle = length × width; round = 3.1416 × radius²; oval = 3.1416 ÷ 4 × length × width
- Average depth = (shallow end + deep end) ÷ 2, measured to the water, not the wall top
- Cubic feet = surface area × average depth
- Gallons = cubic feet × 7.48
Worked example
A 16 × 32 ft in-ground pool with 3.5 ft of water at the shallow end and 8 ft at the deep end: surface 512 sq ft × average depth (3.5 + 8) ÷ 2 = 5.75 ft = 2,944 cu ft. × 7.48 = 22,023 gallons.
Gallons in common pool sizes
Round above-ground pools
By diameter and the depth of the water (not the wall height).
| Diameter | 42 in. water | 48 in. water | 52 in. water |
|---|---|---|---|
| 12 ft | 2,961 | 3,384 | 3,666 |
| 15 ft | 4,627 | 5,288 | 5,728 |
| 18 ft | 6,662 | 7,614 | 8,249 |
| 21 ft | 9,068 | 10,364 | 11,227 |
| 24 ft | 11,844 | 13,536 | 14,664 |
| 27 ft | 14,991 | 17,132 | 18,560 |
| 30 ft | 18,507 | 21,151 | 22,913 |
Rectangular in-ground pools
By size and the water depth at the shallow and deep ends, assuming an even slope.
| Size | 3.5 to 6 ft deep | 3.5 to 8 ft deep |
|---|---|---|
| 12 × 24 ft | 10,233 | 12,388 |
| 14 × 28 ft | 13,929 | 16,861 |
| 15 × 30 ft | 15,990 | 19,356 |
| 16 × 32 ft | 18,193 | 22,023 |
| 18 × 36 ft | 23,025 | 27,872 |
| 20 × 40 ft | 28,426 | 34,410 |
Pool volume questions
How many gallons is my pool?
Measure the length and width (or the diameter of a round pool), and the water depth at the shallow and deep ends. Enter them above. The calculator multiplies surface area by average depth and converts cubic feet to gallons at 7.48 per cubic foot. A 16 × 32 pool running from 3.5 to 8 ft deep holds about 22,023 gallons.
How many gallons are in an Olympic swimming pool?
At least 825,538 gallons (3,125 cubic meters, or 3.125 million liters). World Aquatics rules for Olympic Games pools set a length of 50 m, a width of at least 25 m and a depth of at least 2.5 m, so that's the smallest an Olympic pool can be. Many pools built to older rules are shallower and hold less. Source: World Aquatics Competition Regulations, section 16.2.
How many gallons are in a 24 ft round pool?
About 13,536 gallons with 48 in. of water, or 14,664 gallons with 52 in. A pool sold as "24 × 52" has a 52 in. wall, and the water usually sits a few inches below the top, so measure the water itself. The table above covers other sizes.
How do I find the average depth of my pool?
Measure the water depth at the shallow end and the deep end, add them and divide by 2. That assumes the bottom slopes evenly; a pool with a deep hopper in the middle holds a little more or less, so treat the result as close, not exact. For an above-ground pool with a flat bottom, enter one depth and leave the deep end blank.
How do I calculate a kidney-shaped or freeform pool?
Rules of thumb for kidney pools differ from source to source, so this calculator doesn't use one. Instead, find the water surface area: check the builder's plans or the cover or liner size, or split the shape into rectangles and circles with the square footage calculator. Then choose "Freeform" and enter the square feet and depths.
How long does it take to fill a pool with a garden hose?
Divide the gallons by your hose's flow in gallons per minute, then by 60 for hours. To measure the flow, time how long the hose takes to fill a 5-gallon bucket: 5 ÷ seconds × 60 = gallons per minute. If it takes 30 seconds (10 gal/min), a 24 ft round pool with 48 in. of water takes about 22 hr 34 min. Enter your fill rate above to get your own time.