Calculate Pool Volume – Calculator for m³ and Liters
Pool guide · Dimensions & water volume
How many litres does your pool hold? Calculate pool volume in cubic metres and litres for a rectangular, round or elliptical pool. Use the pool’s internal dimensions and actual water depth.
Pool volume – calculator
Enter all measurements in metres. Water depth is measured from the bottom to the water surface. With a uniformly sloping floor, use the average of the shallow and deep water depths.
Example: 8 × 4 × 1,4 metres gives approximately 44,8 m³ or 44 800 litres before deducting for a ladder and other built-in features.
The result is a geometric estimate before deducting for steps, benches and other parts that take up space. 1 m³ = 1 000 litres. An oval is calculated as an ellipse, not as a pool with straight long sides and semicircular ends.
How to measure for a useful estimate
- Measure the inside. The pool’s external dimensions and excavation dimensions should not be used for the water volume.
- Measure the water level. A structure listed as 1,5 metres deep does not normally contain water all the way to the top edge. Enter your measured water depth.
- Take the bottom shape into account. With a uniform slope and the same width לאורך the pool, you can use the average depth. Example: (1,2 + 1,6) ÷ 2 = 1,4 metres.
- Adjust for built-in features. A ladder, bench seat and shallow sun shelf reduce the water volume. Use the manufacturer’s volume figure when it describes your setup and your water level.
Formulas for pool volume
| Shape | Volume in m³, with dimensions in metres |
|---|---|
| Rectangular pool | Length × width × average water depth |
| Round pool | π × (diameter ÷ 2)² × water depth |
| Oval pool as an ellipse | π × length × width ÷ 4 × average water depth |
Does your pool have straight long sides with semicircular ends? Split the surface into a rectangle and a circle, calculate each part separately and add them together. An irregular shape, multiple bottom levels or a heavily varying width should also be divided into simpler shapes for a better estimate.
Example: how many litres are in the pool?
| Internal dimensions | Water depth | Volume | Litres |
|---|---|---|---|
| Rectangular 3 × 6 m | 1,4 m | 25,2 m³ | 25 200 |
| Rectangular 4 × 8 m | 1,4 m | 44,8 m³ | 44 800 |
| Round, diameter 4 m | 1,2 m | About 15,08 m³ | About 15 080 |
| Ellipse 6 × 3 m | 1,4 m | About 19,79 m³ | About 19 792 |
The examples are idealised shapes without steps or other built-in features. Rounding may create small differences between m³ and litres.
What do you use the pool volume for?
The volume is a basis when planning water filling, discussing circulation and following dosing instructions for pool chemicals. For chemical dosing, you also need current measured values and the instructions for the product you use. Volume alone does not say how much treatment is needed.
For choosing a pump, the filter, pipework, resistance and connected equipment must also be assessed. You can use our pool pump electricity consumption calculator when you have power and operating time.
Frequently asked questions
How many litres are in a cubic metre?
One cubic metre, 1 m³, is exactly 1 000 litres. So multiply the volume in m³ by 1 000.
What water volume does a 4 × 8 metre pool have?
With internal dimensions of 4 × 8 metres and a water depth of 1,4 metres, the geometric volume is 44,8 m³, that is 44 800 litres. Steps and benches reduce the amount of water.
Can I use the pool’s stated depth?
Only if it really refers to the water depth at your water level. Structural depth and actual water level are different measurements.
Which figure gives the most accurate water volume?
A documented volume for the exact model and water level, or a water meter during a full fill, provides a better basis than a simplified geometric calculation. Subtract water used for other purposes during the measurement.
Planning a new pool?
Consider the dimensions you want, the site conditions and how you want to use the pool. We can help you compare suitable models.
