Swimming Pool Volume Calculator

Select your pool shape, then enter the dimensions to calculate the surface area and volume (size) of your pool!

It can calculate the volume for rectangular/square, circular/oval and even kidney shaped pools. Results are in cubic metres and litres (metric).


Pool Surface Area: 36.0 m²

Pool Volume: 72.0 m³ (72,000 L)

Why Calculate Your Pool's Volume?

Water Chemistry

Every single thing to do with pool chemistry depends on concentrations, not on absolute amounts.

For this reason, calculating your pool's volume is absolutely crucial to knowing how much of each chemical you need to add to your pool.

Here's a list of a few important chemicals in your pool that you need to know your volume in order to be able to monitor properly:

  • Chlorine
  • Cyanuric acid
  • Alkalinity
  • Phosphates
  • Salt
  • Metals
  • Dissolved solids/salts

Keep in mind that pH is one of the few important parts of your water chemistry that does not depend on your volume (that's because it's already a concentration - the concentration of H⁺ ions in your water).

Pool Design

This calculator can also be useful if you are in the process of designing your pool. As you enter your proposed pool dimensions, the diagrams will automatically update and you can start to see what your finished pool may end up looking like.

You can then tweak the dimensions slightly and see how this will affect the shape and look of your pool.

How To Calculate Swimming Pool Volume?

The formula for calculating your swimming pool volume depends on the type of pool you have.

Rectangular/Square Swimming Pool

If you have a rectangular or square pool, you're in luck - this is the easiest pool to calculate the volume for. The formula is:

Volume = Length x Width x Average Depth

If you don't know the average depth of your pool, take the average of the depth of the shallow end and the depth of the deep end.

Circular/Oval Swimming Pool

The volume calculation for these pools is also pretty straightforward:

Volume = π x (Length / 2) * (Width / 2) * Average Depth

Kidney Shaped Swimming Pool

Here's how to calculate the volume of one of these:

Volume = Length x (Long Width + Short Width) x Average Depth x 0.45

The long width and short width refer to the width at the widest point of the larger bulge and smaller bulge in your pool. Refer to the diagram in the calculator above for more information.

How To Use This Swimming Pool Calculator?

Select Pool Shape

Begin by selecting your pool shape. You can choose from the following:

  • Rectangular/Square
  • Circular/Oval
  • Kidney

This will bring up a diagram of your selected pool shape.

Enter Pool Dimensions

For rectangular/square and circular/oval pools, simply enter the length, width and average depth of your pool. If you aren't sure what the average depth of your pool is, take the average of the short end depth and the deep end depth.

For kidney shaped pools, you will need to enter two widths rather than one. The width of the larger bulge and the smaller bulge.

As you enter your dimensions, the pool diagram will automatically animate and adjust according to your entered dimensions. This acts as a double check so that you can make sure that your entered dimensions are correct.

Check Pool Volume

The calculator will now display your pool's surface area (in square metres) and volume (in cubic metres and litres).

If you are still in the design phase of your pool, feel free to tweak the dimensions and see how your pool's shape and look changes with these new dimensions.

Found a problem with the calculator? Send me a message and I'll fix it as soon as I can.

Louis from Pool Advisor


A chemical engineer by trade, Louis is committed to debunking myths in the pool industry by explaining the underlying chemistry and making it accessible to all.