How To Calculate Pool Volume

Like a novice cook who needs to know how much of each ingredient to add to a dish, pool owners need to know how much of their maintenance products they need to add to their water. In order to do this properly, pool owners must know their pool volume — how much water is actually in their pool.

Calculating your pool volume is essential to correctly balancing the water. Making only rough estimates can result in errors and end up causing issues. Over-estimating is a waste of money; under-estimating will result in unsanitary water. If the volume of your pool isn't in the original documentation, it's easy to calculate it yourself.

Running The Numbers

Three average measurements are used to calculate pool volume: length, width, and depth. There are more complicated formulas for measuring oddly-shaped pools, but we'll focus on the traditional pools.

First, carefully record the measurements mentioned above. Second, take each number and multiply them together. Finally, multiply that result by 7.5 (which is approximately how many gallons are in a cubic foot).

The combined formula should look like this:

Length × Width × Depth × 7.5 = Pool Volume (in Gallons)

Once you have this number, you should be able to apply the correct amount of pool chemicals to your pool water and avoid any future dosage issues.

Quick Reference

For your convenience, you can also consult the following charts. They detail the volume of many popular pool sizes.

Above Ground Pool Volume (48″ Wall Height)

Pool Size	Gallons
15′ Round	5,300
18′ Round	7,600
20′ Round	9,400
24′ Round	13,600
27′ Round	17,200
28′ Round	18,500
11×25 Oval	6,500
11×30 Oval	7,800
15×25 Oval	8,900
15×30 Oval	10,600
18×33 Oval	14,000
18×38 Oval	16,100

Above Ground Pool Volume (52″ Wall Height)

Pool Size	Gallons
15′ Round	5,800
18′ Round	8,300
20′ Round	10,200
24′ Round	15,300
27′ Round	18,600
28′ Round	20,000
11×25 Oval	7,000
11×30 Oval	8,400
15×25 Oval	9,600
15×30 Oval	11,500
18×33 Oval	15,200
18×38 Oval	17,500

In-Ground Pool Volume (Standard Depth)

Pool Size	Gallons
12×24 Rectangle	10,800
16×32 Rectangle	19,200
16×36 Rectangle	21,600
18×36 Rectangle	24,300
20×40 Rectangle	30,000
16×32 Oval	17,200
18×36 Oval	21,700
18×36 Oval	21,700
20×40 Oval	26,800
17×33 Grecian	19,700
17×37 Grecian	22,200
20×36 Grecian	24,300
20×44 Grecian	30,300
16×30 Kidney	14,900
16×34 Kidney	16,500
20×38 Kidney	20,200

For more information on pool size or chemical usage, check our complete blog library, or reach out to one of our knowledgeable staff members at your local Leslie's store. At Leslie's, your pool is our passion.