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Rainwater tank calculator for Canberra

Canberra averages about 615 mm of rain a year (long-term average at the Bureau of Meteorology’s Canberra Airport station). Every square metre of roof collects roughly 1 litre per millimetre of rain, so a typical Canberra home can harvest a lot of water.

Rain you can collect in a year

Roof areaMetal roof (×0.9)Tiled roof (×0.8)Average per day (metal)
80 m²44,280 L39,360 L121 L
100 m²55,350 L49,200 L152 L
150 m²83,025 L73,800 L227 L
200 m²110,700 L98,400 L303 L
250 m²138,375 L123,000 L379 L
300 m²166,050 L147,600 L455 L

Work it out for your roof

The calculator below is pre-filled with Canberra’s average rainfall. Change the roof area, daily use and tank size to match your home.

Your measurements

Rainwater tank calculator

Estimates only. Check sizes, coverage and quantities with your supplier, engineer or certifier before ordering. Standards references are a guide, not compliance advice.