Oval Pool Volume: Formula and Gallons Chart

The oval formula

Oval pool volume in gallons = length x width x average depth (all in feet) x 6.7. Measure the length and width at the longest and widest points, straight across.

Why 6.7 and not something else? A true ellipse with the same length and width would use a multiplier of about 5.87 (that is 7.48 times pi divided by 4). But real oval pools are not true ellipses: they have straight wall sections between the curved ends, and those straight sections hold extra water. The industry-standard 6.7 multiplier reflects that real shape, sitting between the pure ellipse (5.87) and the full rectangle (7.48). In effect, an oval holds about 90 percent of the water a rectangle with the same overall dimensions would hold: 6.7 / 7.48 = 0.896.

How to calculate the volume of an oval pool

Worked example: a 15 by 30 foot oval, 3.5 feet in the shallow end, 5.5 feet in the deep end.

1. Average depth: (3.5 + 5.5) / 2 = 4.5 feet.
2. Rectangle-equivalent cubic feet: 15 x 30 x 4.5 = 2,025.
3. Gallons: 2,025 x 6.7 = 13,568 gallons.

So the answer to "how many gallons is my 15x30 oval pool" is about 13,500 gallons at typical depths. In liters: 13,568 x 3.78541 = about 51,360 liters.

Oval pool gallons chart

Oval size (ft)	Average depth	Gallons
12 x 24	4.25 ft	8,201
14 x 28	4.5 ft	11,819
15 x 30	4.5 ft	13,568
16 x 32	4.75 ft	16,294
18 x 33	4.5 ft	17,909

That also answers "how many gallons does a 16x32 oval pool hold": about 16,294 gallons at a 4.75 foot average depth, or roughly 17,150 at a full 5 feet.

Oval vs round vs rectangle: which holds more?

Take a 30 foot overall length as a fixed yard constraint. A 15 by 30 oval at 4.5 feet deep holds 13,568 gallons. A 30 foot round pool at the same depth would hold 30 x 30 x 4.5 x 5.9 = 23,895 gallons, far more, but it needs a 30 foot wide yard. A 15 by 30 rectangle would hold 15,148 gallons at 4.5 feet (15 x 30 x 4.5 x 7.48). The oval trades about 10 percent of the rectangle's volume for softer corners and a shape that fits narrow lots better.

Above ground ovals

Oval above ground pools use the same 6.7 formula with the water depth (wall height minus 6 to 8 inches). A 12 by 24 oval with 4 feet of water holds 12 x 24 x 4 x 6.7 = 7,718 gallons. A 15 by 30 oval with 4 feet of water holds 12,060 gallons. See above ground pool volume by size for the full round and oval chart.

How big is a 10,000 gallon pool?

Roughly a 12 by 24 foot oval at about 5 feet of average depth (12 x 24 x 5 x 6.7 = 9,648 gallons), or a 15 foot round pool a little deeper than standard. In rectangular terms, it is close to a 12 by 24 foot pool at 4.5 feet deep (9,695 gallons). Ten thousand gallons is a comfortable small-to-mid-size pool: enough for a family, modest to heat and maintain.

Check your own oval: the free pool volume calculator has a dedicated oval mode with the 6.7 formula built in.