Pump and filtration
Volume helps establish the required pump flow. Insufficient circulation makes it harder to filter the water effectively and maintain clarity.
Calculators
Water volume
Pool volume calculator: cubic metres and litres
Enter the shape and internal dimensions to estimate water volume in cubic metres and litres for equipment sizing and dosing.
Calculator
Enter the pool shape and dimensions
Use actual water depth. The calculator averages the shallowest and deepest values, which assumes a level or uniformly sloping floor. Calculate irregular or stepped sections separately.
Quick examples
Why it matters
Why you need to know your pool’s water volume
Volume affects pump and filter selection, chemical doses, heating time and maintenance costs.
Chemicals and treatments
Chemical dosing starts with water volume. A 10 m³ pool and a 45 m³ pool need different amounts of the same product for the same adjustment.
Water heating
A larger volume needs more heat and takes longer to warm. Size heating for the actual water volume, not external pool dimensions alone.
Seasonal costs
Larger pools generally need more water, electricity, chemicals, filtration and maintenance time. The extra cost does not end with the purchase.
Formulas
How to calculate pool volume
The calculator uses standard formulas for common shapes. For irregular pools, treat the result as an initial estimate and calculate separate sections where necessary.
Rectangular pool
length × width × average depth
8 × 4 × 1.35 = 43.2 m³
Round pool
3.14 × radius × radius × average depth
4.6 m diameter and 1.2 m depth = approximately 19.9 m³
Oval pool
3.14 × half the length × half the width × average depth
7.3 × 3.7 × 1.2 × π ÷ 4 ≈ 25.5 m³
Estimation mistakes
Common mistakes when calculating water volume
A small measurement error can mean several thousand litres in a larger pool.
- 1using maximum depth instead of average water depth
- 2calculating a round pool as if it were square
- 3estimating volume from a model name rather than actual dimensions
- 4choosing a pump by price without checking actual flow
- 5guessing chemical doses without volume and water tests
- 6comparing pool lengths while ignoring differences in width and depth
Understanding the result
How to use the result
Use the volume when selecting equipment, estimating doses and planning costs. For irregular shapes, refine the estimate rather than adding an arbitrary allowance to chemical doses.
Pump flow rate
Once you know the volume, check whether the pump delivers enough flow for the intended filtration schedule.
Learn moreChemical dosage
Do not guess chemical doses. Water volume is essential to any dosing estimate.
Learn moreCosts and budget
Volume affects equipment, heating, water, electricity and maintenance throughout the season.
Learn moreFAQ
Pool volume questions answered
Is 1 m³ the same as 1,000 litres?
Yes. One cubic metre holds 1,000 litres. Multiply cubic metres by 1,000 to convert to litres.
Which depth should I enter for a shallow and deep end?
Enter the minimum and maximum water depths. The calculator averages them, which works for a uniformly sloping floor. For stepped floors or irregular depth changes, calculate separate sections and add them together.
Is the result exact?
It is a practical estimate. Wall shape, water level, steps, benches and construction details can change the actual volume.
Why calculate volume before buying a pump?
The pump must circulate sufficient water through the filter within the planned schedule. Inadequate flow for the volume makes clear water harder to maintain.