# What is my pool’s volume?

Computes the water volume of a rectangular, round or oval pool from its length, width or diameter and its shallow and deep end depths, in US gallons, litres, cubic feet and cubic metres.

- Page: https://www.acalculator.org/construction/pool-volume-calculator
- JSON spec: https://www.acalculator.org/construction/pool-volume-calculator.json
- Version: cfa2d264b864

## Default answer

Example with the default inputs (Shape Rectangle, Length 32 ft, Width 16 ft, Shallow end depth 3.5 ft, Deep end depth 6 ft): The pool holds about 18,193 gal of water.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| shape | Shape | The shape of the pool from above. |
| len | Length | The inside length of the pool. |
| wid | Width | The inside width of the pool. |
| dia | Diameter | The inside diameter of the round pool. |
| shallow | Shallow end depth | The water depth at the shallow end. |
| deep | Deep end depth | The water depth at the deep end. Enter the same depth for a pool with a flat floor. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| gallons | Water | The volume of water in US gallons. |
| liters | Litres | The volume of water in litres. |
| cubicFeet | Cubic feet | The volume of water in cubic feet. |
| cubicMeters | Cubic metres | The volume of water in cubic metres. |
| averageDepth | Average depth | The mean of the shallow and deep end depths. |

## Method

volume = surface area × (shallow depth + deep depth) ÷ 2; rectangle: length × width; round: π × diameter² ÷ 4; oval: π × length × width ÷ 4

## Assumptions

- The floor slopes evenly from the shallow end to the deep end, so the average depth is the mean of the two. A hopper or a sharp break in the floor changes the volume.
- An oval is a true ellipse. Pools with straight sides and round ends hold more.
- Sizes are inside the walls, and depths are to the water line, not the top of the wall.
- Gallons are US gallons of 231 cubic inches.

## Worked examples

1. shape = rectangle, len = 9.7536, wid = 4.8768, shallow = 1.0668, deep = 1.8288 gives cubicFeet = 68.866571, gallons = 68.866571. Source: hand calculation in content.mdx: 32 × 16 × (3.5 + 6) ÷ 2 = 2,432 ft³ × 1,728 ÷ 231 = 18,193 gal.
2. shape = round, dia = 7.3152, shallow = 1.2192, deep = 1.2192 gives cubicFeet = 51.240958. Source: hand calculation in content.mdx: π × 24² ÷ 4 × 4 = 576π = 1,809.6 ft³ = 13,536 gal.
3. shape = oval, len = 9.144, wid = 4.572, shallow = 1.3716, deep = 1.3716 gives cubicFeet = 45.035999. Source: hand calculation in content.mdx: π × 30 × 15 ÷ 4 × 4.5 = 1,590.4 ft³ = 11,897 gal.
4. shape = rectangle, len = 10, wid = 5, shallow = 1.2, deep = 1.8 gives cubicMeters = 75, liters = 75, gallons = 75. Source: hand calculation in content.mdx: 10 × 5 × (1.2 + 1.8) ÷ 2 = 75 m³ = 75,000 L = 19,813 gal.

## FAQ

### How do I calculate how many gallons are in my pool?

Work out the volume in cubic feet, then multiply by 7.48, the number of US gallons in a cubic foot (1,728 ÷ 231). A 32 ft × 16 ft pool with an average depth of 4.75 ft holds 2,432 ft³, or about 18,193 gallons.

### How do I handle a shallow end and a deep end?

Average the two depths: (shallow + deep) ÷ 2. This assumes the floor slopes evenly. For a flat floor, enter the same depth twice.

### How do I calculate a round pool?

Multiply π × diameter² ÷ 4 by the depth. A 24 ft round pool 4 ft deep is π × 576 ÷ 4 × 4 = 1,809.6 ft³, or about 13,536 gallons.

### Why does the pool volume matter?

Pool chemicals are dosed per volume of water, and heaters, pumps and filters are sized by it. The label on a chemical tells you the dose per 10,000 gallons or similar; follow it with your pool’s volume.

### Should I measure to the top of the wall?

No. Measure the depth to the water line, and the length and width inside the walls. Measuring to the top of the wall overstates the water.

### How many litres are in a US gallon?

A US gallon is exactly 3.785411784 litres. 1 cubic metre is 1,000 litres, or about 264.2 US gallons.

## Sources

- NIST SP 811 (2008), Appendix B: 1 US gallon = 231 in³ = 3.785411784 L exactly; 1 ft = 0.3048 m exactly.