Pool gallons by size, shape and water depth
Approximate US gallons for common pool sizes, using the standard multipliers (rectangular 7.5, round/oval 5.9 × length × width × average depth). Round and above-ground pools are listed by diameter and water depth, because the same 18 or 24 ft pool holds very different amounts depending on how deep it is filled. Measure your own pool and use the volume calculator for an exact figure.
Rectangular pools (avg depth 4.5 ft)
| Size (ft) | Gallons |
|---|---|
| 12 × 24 | 9,694 |
| 14 × 28 | 13,195 |
| 16 × 32 | 17,234 |
| 18 × 36 | 21,812 |
| 20 × 40 | 26,928 |
| 16 × 40 | 21,542 |
Round / above-ground pools, by diameter and water depth
| Diameter (ft) | 3.0 ft (36 in) | 3.5 ft (42 in) | 4.0 ft (48 in) | 4.5 ft (54 in) |
|---|---|---|---|---|
| 8 | 1,128 | 1,316 | 1,504 | 1,692 |
| 12 | 2,538 | 2,961 | 3,384 | 3,807 |
| 15 | 3,965 | 4,626 | 5,287 | 5,948 |
| 16 | 4,512 | 5,264 | 6,016 | 6,768 |
| 18 | 5,710 | 6,662 | 7,614 | 8,565 |
| 21 | 7,772 | 9,068 | 10,363 | 11,658 |
| 24 | 10,152 | 11,844 | 13,535 | 15,227 |
| 27 | 12,848 | 14,989 | 17,131 | 19,272 |
| 30 | 15,862 | 18,506 | 21,149 | 23,793 |
Above-ground pools are sold by wall height — usually 48, 52 or 54 in — but they are filled below the top rail, so read the column for the actual water depth rather than the wall. For a diameter or depth not listed, use the round pool calculator.