Do you want a garden pool? Or just a children’s pool? Then it is essential to consider the cost of purchase, how much water you need for the pool, and how much it costs to refill once. With this calculator, you can quickly get the amount of water you need for a pool or children’s pool, along with the cost of water.

This calculator is also useful when calculating how much chlorine you need for your pool. The ideal chlorine combination is between 1 and 3 parts per million (ppm). If you do not want to use chlorine, you can also use pool salt as an option for pool disinfection. Pool salt is actually standard sodium chloride (NaCl).

Take a look other related calculators, such as:

How to Calculate Volume

When calculating the volume in cubic meters, you need to consider what geometric body your pool is. Then you need to know the length, width, and two depths of the pool. Use two depths if your pool is not the right shape or take the deepest and shallow part of the pool.

How does the pool volume calculator work?

To calculate the pool volume using our calculator, simply enter the following values:

pool shape, dimensions: width, length, depth 1, depth 2.

You need to enter all measured values ​​in the same units. If you measure the width in meters, you will also measure all other parameters in meters and enter them in the calculator. Other units of measurement in which you can express the dimensions of your pool are centimeters, inches, feet, and yards.

Once you have entered all the measured pool elements, the calculator will calculate the volume of your pool itself. 

Formulas behind pool calculator

Below you can read the formulas for calculating the amount of water in your pool by shape. Use the units that are easiest for you.

Pools with a constant depth

Length multiplied by width means the surface of the pool. Multiply the result obtained by the average depth, and you will get the volume in cubic meters. You can use the Average calculator to calculate the average.

Measure the pool’s length, width, and average depth and round all the measured values to the nearest meter.

If the shallower depth is 1.5 m and the deeper 2 m, then we can conclude that the slope of the pool bottom is gradual, the average depth is 1.75 m.

• Average depth = (shallow end depth + deep end depth) / 2

D_{avg} = \frac{1.5+2}{2} = 1.75m

Different average depth

If most of the pool is shallow and suddenly falls deep into the water, you have a different average depth. In this case, you can treat the pool as two parts. Measure the shallow end’s length, width, and average depth, then take the exact measurements for the deeper part. Calculate the pool volume of the shallow part and add it to the volume you calculated for the deeper part.

Be sure to use the actual water depth in your calculations, not the depth of the container. Calculating the exact amount is critical because of serious mistakes when adding chemicals based on water volume.

How many gallons is my pool?

When you want to know how many gallons are in your pool, use the same formula for cubic meters.

To begin with, use the calculator to determine the shape of your pool, i.e., whether it is rectangular or oval. After selecting the pool shape option, enter the pool length, width, and depth values ​​in feet in the drop-down boxes. In the calculator, determine the rate for all dimensions as the unit of measurement.

For example, if you have that width = 7 feet, length = 13 feet, and depth from 4 to 6 feet, the pool volume is 3 403.65 gal US.

Or simply, no matter in which units of measurement the dimensions are expressed, the calculator will automatically convert the pool volume into the chosen option by selecting the desired unit.

Olympic swimming pool volume

The Olympic pool must be following standardized dimensions to be large enough for international competitions. This type of pool they also use at the Olympic Games, where the length of the pool is 50 meters (164.0 feet), and the width is 25 meters (82 feet), the minimum depth is 2 meters (6 feet).

Considering the standard dimensions of the Olympic pools using our calculator, we obtained that the volume of the Olympic pool is 3.125 m3.

Irregular Shapes

Renal pools

Renal pools have a typical kidney shape. All sides of the pool are rounded, but the “rectangular” shapes have been preserved.


L pools are L-shaped pools. They are ideal for children to play in one part of the pool while others can swim undisturbed in the other part of the pool, yet these pools take up a lot of space.

Greek pools

Greek pools are rectangular pools whose corners are neither round nor flat. They are pretty sloping and equipped with mosaic or printed pool lining.

Lagoon pools

Lagoon pools have a very jagged “lagoon” shape. There are no right angles to see. Such decorative pools are expensive and ideal for accommodation in a natural environment with many flowers and plants.

Roman pools

The Roman pool has a very classic look and consists of curves. We can find this shape in many Roman buildings.


1. How to calculate how much water is in my pool?

First, you need to measure the pool’s width, length, and depth. Simply enter it into the calculator once you have collected all the data. The calculator will automatically calculate how much water is in your pool. You can use any unit of measurement on our calculator, and you need to adjust it to your needs.

2. How many gallons is a 10×25 pool?

If your pool has a width = 10 feet and a length of 25 = feet, we will consider that the average pool depth = 3.5 feet, in which case the pool volume is 7,854.57 US gal.

3. How to calculate the volume of a round pool?

You can calculate the volume of a round pool with this formula:
π x radius squared x mean depth = volume (in cubic meters), where
π is a constant pi, 3.14, and the radius is half the diameter.
Therefore, after measuring the distance at the widest part of the circle, divide the result obtained by two, and get the radius. For example, if the diameter is 4 m, we can halve that value by a radius of 2 m. To find the radius squared, multiply 2 m by itself to get 4 m squared.
For this example, the result will be 3.14 x 4 m 2 x 1.75 m = 21,98m3