The short answer
Pool volume drives every equipment and chemical decision. For a rectangle: length × width × average depth × 7.48 gallons per cubic foot. Round and oval pools use 5.9 instead of 7.48; kidney and freeform pools roughly 6.7. Our pool volume calculator does the math.
Examples
| Pool | Math | Gallons |
|---|---|---|
| 16 x 32 ft, 3.5-6 ft deep | 16 x 32 x 4.75 x 7.48 | about 18,200 |
| 24 ft round, 4 ft deep | 24 x 24 x 4 x 5.9 | about 13,600 |
| 15 x 30 ft oval, 4 ft deep | 15 x 30 x 4 x 5.9 | about 10,600 |
What it's used for
- Pump flow: gallons / (turnover hours x 60).
- Salt system rating: at least 1.25 x gallons.
- Heater size: gallons x 8.34 x degrees / hours.
- Chemical doses from product labels.
Products mentioned
Questions readers ask
How many gallons is my above-ground pool?
Diameter x diameter x water depth x 5.9 for round pools; use the water depth, not the wall height.
What is average depth?
(Shallow end + deep end) / 2 for a pool with a constant slope.