How To Calculate Pool Volume
Calculate Pool Volume
“How many gallons are in my pool?” This is a question that all pool owners need to know the answer to in order to properly understand chemical dosages and receive help from pool professionals. Whether your pool is kidney-shaped, oval, rectangle, or “L” shaped, knowing some basic pool volume calculations will help you get an estimate of how much water the pool holds.
Sparkling clean, clear pool water can only be achieved by maintaining the right balance of chemicals in your pool. In order to do this, pool owners need to know their pool size in gallons, so that they can add the right amount of pool products, such as muriatic acid or chlorine, when needed. Whether you have a big or small pool size, taking a guess at it usually results in pool water that is out of balance, causing algae growth, cloudiness, and even corrosion.
Basic Pool Volume Calculations
The first step in calculating your pool’s volume is knowing what shape your pool is categorized as; you’ll also want to see if your pool has a slope. If it does, the change in depth will have an effect on the total volume, so be prepared to account for that. Below we’ll cover the different types of pools and the formulas that need to be used in order to properly calculate the volume.
How to Calculate the Volume of a Rectangular-Shaped Pool
You can determine the volume of a rectangular shaped pool with some simple measurements and a calculator.
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Start by measuring how long and how wide your pool is, in feet.
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Next, you need to find the pool depth. Unless your pool is the same depth throughout, you will need to calculate the average depth.
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For a pool that gradually slopes from one end to the other, you’ll first need to calculate the average depth of your pool. This can be done using the following formula: (Depth in shallow end + Depth in deep end) / 2 = Average dept(ft)
If you’re confused about how to use this formula, here is an example of how it can be applied: If a pool’s depth is 3ft in the shallow end and 9ft in the deep end, you would have an average depth of 6ft. (3+9)/2=6.
Now that you’ve calculated the average depth of your pool, you can use plug the average pool volume into the following formula to calculate the total pool volume: Length(ft) x Width(ft) x Depth(ft) x 7.5(gallons of water per cu ft) = Pool Volume (gallons)
To keep things simple, we’ll continue with the example that we started earlier where we calculated the average depth of our pool - in this scenario, the average depth was 6ft. Let’s say that our 6ft deep pool was 12ft by 36ft. Using the total pool volume formula mentioned above, we can plug these values into our formula. Here’s what that would look like: (36 x 12 x 6 x 7.5 = 19,440). So, our total pool volume in gallons is 19,440.
If you have a pool that drops off steeply or is an irregular shape, it may be helpful to divide the pool into multiple sections. You can calculate the volume for each section and then add the numbers together to determine the total volume of your pool.
How to Calculate the Volume of a Kidney-Shaped Pool
Calculating the volume of a kidney-shaped pool is similar to calculating the volume of a rectangle-shaped pool. Since most pools have a slope, you’ll want to begin by calculating the average depth using the same formula that we included earlier in this article.
Once you know the average depth of your pool, you can use the following formula to calculate the volume of a kidney-shaped pool: Volume = Length x Width x Avg. Depth.
How to Calculate the Volume of an L-Shaped Pool
Calculating the volume of an L-shaped pool is actually easier to do than you might think. In fact, the formula for doing this is the same as what we use to calculate the volume of a rectangular pool, only with an extra step. If you have an “L” shaped pool, you can split each section into 2 rectangles, then use the same volume formula listed above for each section, adding the results together to get the total volume for your pool.
Doheny’s Pool Volume Calculator
If your pool is a standard size and shape, you don’t even need to do any math! Check out these handy charts to determine the volume of popular pool sizes.
Above Ground Pools with 48-inch Wall Height
|
Pool Size and Shape |
Pool Volume in Gallons |
|
15 ft Round |
5,300 |
|
8 ft Round |
7,600 |
|
20 ft Round |
9,400 |
|
24 ft Round |
13,600 |
|
27 ft Round |
17,200 |
|
28 ft Round |
18,500 |
|
11×25 ft Oval |
6,500 |
|
11×30 ft Oval |
7,800 |
|
15×25 ft Oval |
8,900 |
|
15×30 ft Oval |
10,600 |
|
18×33 ft Oval |
14,000 |
|
18×38 ft Oval |
16,100 |
Above Ground Pools with 52-inch Wall Height
|
Pool Size and Shape |
Pool Volume in Gallons |
|
15 ft Round |
5,800 |
|
18 ft Round |
8,300 |
|
20 ft Round |
10,200 |
|
24 ft Round |
15,300 |
|
27 ft Round |
18,600 |
|
28 ft Round |
20,000 |
|
11×25 ft Oval |
7,000 |
|
11×30 ft Oval |
8,400 |
|
15×25 ft Oval |
9,600 |
|
15×30 ft Oval |
11,500 |
|
18×33 ft Oval |
15,200 |
|
18×38 ft Oval |
17,500 |
Standard Depth Inground Pools
|
Pool Size and Shape |
Pool Volume in Gallons |
|
12×24 ft Rectangle |
10,800 |
|
16×32 ft Rectangle |
19,200 |
|
16×36 ft Rectangle |
21,600 |
|
18×36 ft Rectangle |
24,300 |
|
20×40 ft Rectangle |
30,000 |
|
16×32 ft Oval |
17,200 |
|
18×36 ft Oval |
21,700 |
|
18×36 ft Oval |
21,700 |
|
20×40 ft Oval |
26,800 |
|
17×33 ft Grecian |
19,700 |
|
17×37 ft Grecian |
22,200 |
|
20×36 ft Grecian |
24,300 |
|
20×44 ft Grecian |
30,300 |
|
16×30 ft Kidney |
14,900 |
|
16×34 ft Kidney |
16,500 |
|
20×38 ft Kidney |
<20,200 |
Whether you have a large 30,000-gallon pool, or a small swimming pool with less than 10,000 gallons, knowing your pool size will help you keep your pool water perfectly balanced. If you need help determining the size of your swimming pool, or what chemicals to add to your pool, contact Doheny’s pool pros at 800-574-7665, or visit us online at doheny.com.
