Common Pool Sizes & Their Capacity In Gallons

Having a swimming pool in your backyard can be one of the most fun and relaxing ways to enjoy your home. Depending on your budget and the amount of space available, you can have a pool of almost any size, but it’s important to know how many gallons of water it can hold. Knowing this information can help you maintain your pool and fully understand what chemicals you should add to it. Let’s take a look at how many gallons are in a normal swimming pool.

How Many Gallons of Water Are in an Average In-Ground Pool?

Because pools come in all shapes and sizes, there’s really no such thing as a “normal swimming pool.” However, many in-ground pools are rectangular or oval and fall somewhere between 10 x 20 and 20 x 40 feet. Some common sizes are 15 x 30, 16 x 32, 16 x 36, and 18 x 36 feet. Keep in mind the depth of your pool will also play a role in how much water it holds. A traditional underground pool has a shallow end that’s around 3.5 feet deep and gradually gets deeper.

How Many Gallons of Water Are in an Average Above-Ground Pool?

Above-ground pools are typically round, and the average diameter can range from as small as 10 feet to as large as 24 feet. Some common sizes are 15, 18, 21, and 24 feet. As with in-ground pools, the depth of the pool will impact these numbers. The average above-ground pool is the same depth all around, which is usually 4 to 4.5 feet.

Why Is It Important to Know the Volume of My Pool?

Understanding the volume of water in your pool is essential for maintaining it. For example, the size of your pool impacts how long you should run the filter and pump each day to ensure your water stays clean without wasting power. 

The volume of the pool also impacts the chemistry of the water. When adding chemicals, always make sure you have the correct amount. Add too little, and they won’t work effectively. Add too much, and they can damage your equipment and even your body when you swim. Either way, not adding the right amount could be costly.

How Many Gallons of Water Are in My Pool?

If you know the size and depth of your current swimming pool, it’s easy to calculate the volume or the number of gallons of water it holds. For a rectangular or square pool, use this formula: length x width x average depth x 7.5 = total gallons. For a circular pool, use this formula: diameter x diameter x average depth x 5.9 = total gallons. If your pool is oval-shaped, use this formula: length x width x average depth x 5.9 = total gallons. To get the average depth of a pool that isn’t all one depth, add the shallow end plus the deep end together and divide that number by two.
If you haven’t yet built your pool, reach out to San Diego Pools, the pros with decades of experience. We’re one of the premier pool companies in San Diego, and our pool design and construction experts are dedicated to building exactly the pool you want and providing you with the highest-quality service in the industry. To get started on building the pool of your dreams, call us today.