Pool RatioRound above-ground pools by water depth
| Diameter | 3 ft deep | 3.5 ft deep | 4 ft deep | 4.5 ft deep |
|---|---|---|---|---|
| 12 ft | 2,540 | 2,960 | 3,380 | 3,810 |
| 15 ft | 3,970 | 4,630 | 5,290 | 5,950 |
| 18 ft | 5,710 | 6,660 | 7,610 | 8,570 |
| 21 ft | 7,770 | 9,070 | 10,360 | 11,660 |
| 24 ft | 10,150 | 11,840 | 13,540 | 15,230 |
| 27 ft | 12,850 | 14,990 | 17,130 | 19,270 |
| 30 ft | 15,860 | 18,510 | 21,150 | 23,790 |
| 33 ft | 19,190 | 22,390 | 25,590 | 28,790 |
Oval and in-ground pools
| Pool | Depth | Gallons |
|---|---|---|
| 12 × 24 ft oval pool | 4 ft | 6,770 |
| 15 × 30 ft oval pool | 4 ft | 10,580 |
| 16 × 32 ft oval pool | 4 ft | 12,030 |
| 18 × 33 ft oval pool | 4 ft | 13,960 |
| 18 × 40 ft oval pool | 4 ft | 16,920 |
| 18 × 52 ft oval pool | 4 ft | 22,000 |
| 10 × 20 ft pool | 3.5–6 ft | 7,110 |
| 12 × 24 ft pool | 3.5–6 ft | 10,230 |
| 14 × 28 ft pool | 3.5–6 ft | 13,930 |
| 15 × 30 ft pool | 3.5–6 ft | 15,990 |
| 16 × 32 ft pool | 3.5–6 ft | 18,190 |
| 16 × 36 ft pool | 3.5–6 ft | 20,470 |
| 18 × 36 ft pool | 3.5–6 ft | 23,030 |
| 20 × 40 ft pool | 3.5–6 ft | 28,430 |
The formulas
- Rectangle: length × width × average depth × 7.48
- Round: 3.14 × radius × radius × depth × 7.48
- Oval: 3.14 × half the length × half the width × depth × 7.48
- Kidney: 0.45 × (width A + width B) × length × average depth × 7.48
Average depth = (shallow end + deep end) ÷ 2
Frequently asked questions
How many gallons are in a pool per foot of depth?
Multiply the surface area in square feet by 7.48. A 24 ft round pool has 452 sq ft of surface, so each foot of water is about 3,380 gallons.
How many gallons is an average in-ground pool?
A typical 16 × 32 ft in-ground pool, 3.5 to 6 ft deep, holds about 18,190 gallons.
How many gallons is an above-ground pool?
Most hold 5,000 to 30,000 gallons: a 15 ft round pool about 5,300 gallons, an 18 ft about 7,600, a 24 ft about 13,500 and a 30 ft about 21,100 at 4 ft of water.
Can I find my pool volume from my water bill?
Yes, if you fill a new or drained pool: read the meter before and after. Meters often read in cubic feet; multiply by 7.48 for gallons.