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Rainwater tank calculator for Coffs Harbour

Coffs Harbour averages about 1,668 mm of rain a year (long-term average at the Bureau of Meteorology’s Coffs Harbour Airport station). Every square metre of roof collects roughly 1 litre per millimetre of rain, so a typical Coffs Harbour 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 m²120,096 L106,752 L329 L
100 m²150,120 L133,440 L411 L
150 m²225,180 L200,160 L617 L
200 m²300,240 L266,880 L823 L
250 m²375,300 L333,600 L1,028 L
300 m²450,360 L400,320 L1,234 L

Work it out for your roof

The calculator below is pre-filled with Coffs Harbour’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.