The Average Volume Size of a Kidney-Shaped Pool

If you own a kidney-shaped swimming pool, you may wonder how to figure out the pool's water volume. Knowing this information is important when it comes to adding chemicals to the water. Kidney-shaped pools also have variable depths, which will make the job of figuring out the average volume a bit more complicated. Fortunately, figuring out the average volume in a kidney-shaped pool is more a matter of using a simple math formula than anything else.

Figuring out a kidney-shaped pool's volume is a bit more involved than determining a simple rectangular pool's volume.

Pool Volume

Kidney-shaped pools are curved and don't have sharp lines or breaks. You have to know the pool's length, along with the average width and depth, then use a multiplying factor to figure out the volume. The volume formula for a 30-foot long, 15.5-foot average width and 4.5-foot average depth kidney-shaped pool is: 30 x 15.5 x 4.5 x 7.0 = 14,647.5 gallons. Always use a multiplying factor of 7.0 when figuring out a kidney-shaped pool's volume.

Pool Length

To determine the volume of a kidney-shaped swimming pool, you need to know its overall length first. The overall length for a kidney-shaped swimming pool is just a simple linear measurement. Take a tape measure and figure out the length of the pool at its longest point, end-to-end. Once you have the overall length of the pool, you'll need to determine its average width to figure out its volume.

Average Width

Another important measurement for figuring out a kidney-shaped pool's volume is its average width. Determine the average width by measuring the widest points at each end, adding those two figures together then dividing by two. For example, the average width of a kidney-shaped pool that has 14- and 17-foot wide ends is 14 + 17 = 31, then 31/2 = 15.5 average width. For a kidney-shaped pool's volume, once the length and average width have been determined, you'll need the average depth.

Average Depth

You can determine the average depth of a kidney-shaped pool by measuring the depths of the shallow and deep ends. For a kidney-shaped pool, add the deep and shallow end pool depths together and divide by two. A kidney-shaped pool with a 6-foot deep end and a 3-foot shallow end has an average depth of 4.5 feet. An example of an average depth for a kidney-shaped pool is: 6-foot deep end + 3-foot shallow end = 9, then 9/2 = 4.5 average depth.


Pool builders rarely give more than two size dimensions when it comes to kidney-shaped swimming pools. Typically, a kidney-shaped pool's published dimensions are just its overall length and its maximum width. However, you can't figure out a kidney-shaped pool's true volume from just its length and maximum width. There are no averages when it comes to a kidney-shaped pool's size. However, 16-foot (maximum width) by 32-foot pools are recommended to accommodate a full range of play activities.