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Swimming Pool Volume Calculator

Pool volume with a sloping floor, plus the pump flow for a target turnover. A uniformly sloping floor holds exactly what the average depth would, which makes the calculation simpler than it looks.

Also called: swimming pool volume, pool gallons calculator.

Pool shape
m
m
m
m
hours
Volume
82,500

82,500 litres, or 82.5 m³ and 21,794.2 US gallons. Average depth is 1.65 m. A 6 hour turnover needs a pump moving 229.2 litres a minute. The average depth is exact for a uniformly sloping floor. A flat shallow end with a sudden drop needs the sections computed separately.

In cubic metres
82.5
In US gallons
21,794.2
Average depth
1.65
Surface area
50
Pump flow needed
229.2
Chlorine for 1 ppm
82.5
On the sloping floor
The average depth is exact for a uniformly sloping floor. A flat shallow end with a sudden drop needs the sections computed separately.
How this is calculated
Method and background

How this is calculated

The average of the shallow and deep depths gives the effective depth for a floor that slopes uniformly, so the volume is just surface area times that average. Turnover, the time to circulate the whole volume once, is the number pool pumps are sized on, and six to eight hours is the usual target. The chlorine figure is how many grams raise the whole pool by one part per million, which is the practical unit for dosing.

a pool with a uniformly sloping floor holds the same as one at the average depth
A
Surface area

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

a 10 by 5 metre pool

Pool shape
Rectangular
Length or diameter
10 m
Width
5 m
Shallow end depth
1.2 m
Deep end depth
2.1 m
Target turnover time
6 hours

Volume82,500

50 m2 x 1.65 m; 82,500 litres over 360 minutes

Open this example

a flat floor makes the average the depth

Pool shape
Rectangular
Length or diameter
10 m
Width
5 m
Shallow end depth
1.5 m
Deep end depth
1.5 m
Target turnover time
6 hours

Volume75,000

boundary

Open this example

Method and limits

What it assumes

  • A uniformly sloping floor between the two stated depths.

What it deliberately does not model

  • A pool with a flat shallow section and a sudden drop needs the two parts computing separately.
  • Chlorine demand depends on bather load, sunlight and stabiliser level, not on volume alone.

Formula version 1.0.0 · definition 1.0.0 · United States · Report a problem with this calculator

Frequently asked questions

Can I just use the average depth?
For a uniformly sloping floor, yes, exactly. It stops being exact when the floor has a flat section and a separate deep end.
What turnover should I aim for?
Six to eight hours for a domestic pool. Commercial pools are usually required to turn over considerably faster.