This article will help you quickly and accurately calculate your pool volume in gallons, while also providing conversion tools to get your results in a measurement that is familiar to you.
So don’t overwhelm yourself with numbers, simply measure the width, length, and depth of your pool and return to this article to acquire your pool volume in no time.
Determining Your Pool’s Average Depth
The first step to calculating your swimming pool volume is determining the average depth, as this is the number that will replace the “depth” placeholder in the formulas. If you have a completely level pool floor, this will be as simple as measuring from pool rim to the pool bottom, but most pools have varied depths.
Start by measuring the shallowest point of your pool as well as the deepest point of your pool, then insert your values into this formula:
shallow end depth(ft.) + deep end depth(ft.) / 2 = average pool depth(ft.)
After completing this formula, you now have the average depth you will insert in the following formulas.
Rectangular Pool Volume
The formula used to calculate the volume of your rectangular swimming pool requires your pool length, width, and the average depth you have already calculated.
The formula below is used to not only calculate the volume of your pool, but also to convert your results from cubic foot into gallons. The normal formula for volume is multiplied by 7.5, as one cubic foot is equal to 7.5 gallons, thus converting your result into a more commonly used unit of measurement. This means that the 7.5 can be removed from the equation to get the answer in cubic feet.
Length × width × depth × 7.5 = volume (gallons)
Circular Pool Volume
Similar to the rectangular pool, we use the basic volume formula of a circle and multiply it by the mathematical constant, 7.5, to determine the volume of a circular swimming pool in gallons.
For this formula, you will need the pool dimensions for the average depth of your pool, as well as the radius (diameter × 1/2) of your pool.
3.14 (π) × radius2 × depth × 7.5 = volume (gallons)
Oval Pool Volume
Calculating the volume of an oval pool requires a combination of the rectangular and circular pool formulas,
You will need all the same measurements as you would for a rectangular pool, the length, width and average depth, as well as some numerical constants to factor in the rounded edges.
length × width × 3.14 (π) / 4 × depth × 7.5 = volume (gallons)
Irregular-Shaped Pool Volume
Determining the volume of an irregular pool shape, such as a kidney shape, is a bit more tricky, but still possible.
For these types of pools, you will have to identify circles, squares and rectangles within the pool’s overall shape. The volume of these shapes will then have to be calculated and added together to produce the pool’s overall volume.
While this is certainly a bit more work, it still uses the same basic calculators and measurements required above, so your calculation should go down without a hitch.
Below we have included a calculator to help you convert your measurements and results into the units you are most familiar with.
Pool Volume Reference Chart
We have compiled the measurements for the most common pool sizes below, using the average depths of the types of pools we incorporated.
In-ground Pool Reference Chart
We based the following measurements on the most common in-ground pool sizes, as well as the most common average in-ground pool depths.
|Rectangle dimensions (ft.)||Depth (ft.)||Volume (gal)|
|10 × 20||3||4 500|
|10 × 20||4||6 000|
|10 × 20||5||7 500|
|15 × 30||3||10 125|
|15 × 30||4||13 500|
|15 × 30||5||16 875|
|20 × 40||3||18 000|
|20 × 40||4||24 000|
|20 × 40||5||30 000|
Above Ground Pool Reference Chart
The following dimensions are based on the most commonly available above ground pools on the market and the measurements they provide.
|Circle dimensions (ft.)||Depth (inch)||Volume (gal)|
|Oval dimensions (ft.)||Depth (inch)||Volume (gal)|
|12 × 23||48||6 486|
|12 × 23||52||7 021|
|15 × 30||48||10 575|
|15 × 30||52||11 447|
|18 × 33||48||13 958|
|18 × 33||52||15 110|
|21 × 41||48||20 233|
|21 × 41||52||21 902|
While many parts of pool ownership require a professional hand, determining the volume of your pool can be a completely independent task that costs you no more than a bit of time.
That being said, should your pool prove to be too irregularly shaped to properly calculate the volume of using the methods above, any professional pool installation and maintenance company should be able to provide you with the proper calculations after a pool inspection.
We hope this pool volume calculator has helped you determine pool’s total volume and feel confident in the results.