Part of the Construction & Building suite · 49 calculators

Round Pool Volume Calculator

The water volume of a round pool — with the chlorine dose, fill time and the weight it puts on the ground.

How much water a round pool holds.

Results update as you type
Results
Volume
19,085 L
In cubic metres
In US gallons
Weight of water (tonnes)
Fill time (hours)
Granular chlorine for that rise (g)
Surface area (m²)
Pump flow for a 6-hour turnover (L/min)
Reviewed September 2026. Geometry is the same everywhere; units, bag sizes and sheet sizes follow your region and can be switched. Stair, ramp and structural rules are in the NCC.
No account required · Google Analytics off unless allowedCalculator arithmetic runs in your browserResults update as you type
All calculations run 100% in your browser. The calculator code does not submit your figures to GlobalCalc to obtain a result.
About round pool volume

How the round pool volume calculator works

A round pool is πr²d, using the *average* depth if the floor slopes. For a pool that runs from 1.0 m to 1.8 m, use 1.4 m — not the deep end.

The volume then drives everything else: chemical dosing is per 10,000 litres, filter turnover is sized from it, and the weight it puts on the ground is a tonne per cubic metre.

Formula: V = π r² × average depth

Worked examples

InputsVolumeNote
A 4.5 m pool, 1.2 m deep19,085 L19,085 litres
A larger pool39,584 L39,584 litres
A small above-ground pool5,301 L5,301 litres

Frequently asked questions

Which depth should I use if the floor slopes?

The average of the shallow and deep ends. Using the deep end alone can overstate the volume by half.

How much does the water weigh?

One tonne per cubic metre. A 19,000 litre pool is 19 tonnes, which matters a great deal for above-ground installations and for what is beneath them.

How long does it take to fill?

At a typical 20 L/min garden tap, a 19,000 litre pool takes about 16 hours.

What pump flow do I need?

Enough to turn the whole volume over in about six hours — roughly 53 L/min for a 19,000 litre pool.

How do I dose chlorine?

Granular chlorine at about 65% available chlorine needs roughly 1.5 g per 1,000 litres per ppm. Always follow the product's own directions.

Where these figures come from

Last checked: September 2026. Coverage rates and material sizes are typical manufacturer figures — check the product you buy.