Pool Volume Calculator

Shape

Length, m

Width, m

Average depth, m

Chlorine wanted, mg/l

Active chlorine in the product, %

Result

Volume, m³48
In litres48,000
Product to add, g86
Pump, m³/h8
Per 1 °C of heating, kWh55.8
Surface area, m²32

From geometry to maintenance

Works out pool volume in cubic metres and litres, the chlorine dose for a target concentration, the pump flow required and the energy to warm the water.

Volume matters less on its own than as the basis for everything else. Chemical doses are quoted per cubic metre, pump flow comes from turning the whole pool over in six hours, and heating energy comes straight from the heat capacity of water.

One trap is the active chlorine content of the product. Calcium hypochlorite is about 65 percent active chlorine, dichlor 56, trichlor 90. Dose by the weight of the tablet rather than the active ingredient and you end up at half strength.

What this calculator shows

Pool volume in cubic metres and litres, plus the surface area
The mass of product for your target chlorine level, allowing for its active share
The pump flow required and the energy to raise the water by one degree

What to keep in mind

The pump is sized to turn the whole volume over in six hours — four full cycles a day.
Raising water by one degree takes 1.163 kWh per cubic metre; real consumption is higher because of losses from the surface, especially without a cover.

FAQs

How do I calculate pool volume?

Surface area times average depth. For a rectangle that is length by width; for a circle, pi times the radius squared.

How much chlorine per cubic metre?

One gram of pure active chlorine per cubic metre gives 1 mg/l. Products are never pure, so divide the mass by the active share.

What pump does a pool need?

One that moves the whole volume in six hours. For 48 cubic metres that is 8 m³/h, and the filter is matched to the same flow.

What does heating a pool cost?

1.163 kWh per cubic metre per degree. A cover more than halves the losses — without one, most of the heat leaves the surface overnight.

Worked example

An eight by four above-ground pool

Input: 8 × 4 m, 1.5 m deep, 1 mg/l chlorine, 56% product

Output: 48 m³, 86 g of product, an 8 m³/h pump

Note: Warming that pool by a single degree takes 56 kilowatt-hours. Going from 20 to 26 degrees is 335 kilowatt-hours — several days of a heat pump running.

Useful links

All tools in Home & Utilities

Pool Volume Calculator

Result

Related tools

Water Consumption Calculator

Fertiliser Calculator

Utility Bill Calculator

Useful links