Rainwater Tank Size Calculator Australia | How Much Water Storage Do I Need?

RAINWATER TANK SIZE CALCULATOR

How much rainwater storage do you need?

Tell us where you live, how much roof you can collect from and what you want to use the water for. We’ll model your catchment against historical rainfall and recommend a practical tank configuration.

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Where will the tank be?

Postcode

Rainfall location Optional, but more accurate for large rural postcodes.

Roof catchment area

Use the horizontal footprint of the roof, not the sloping roof surface. Include every roof that can be connected to the tanks.

House roof m² Shed / garage m² Patio / carport m² Other roof m²

Total catchment: 200 m²

Tell us about the property

How many people live here? What water supply do you have?

What do you want the rainwater to supply?

Toilets Laundry Showers Kitchen & bathroom taps Garden / lawn Outdoor taps / cleaning Washing cars Pool / spa top-up Livestock

How much water will you use?

Only the questions relevant to the uses you selected are shown.

Showers

Average shower length minutes Showerhead

Laundry

Washing machine Loads per week

Garden / lawn

Area watered m² Garden type Watering method

Outdoor taps / cleaning

Approximate hose use each week minutes

Car washing

Number of cars Washes per car each month

Pool / spa

Estimated rainwater top-up each week litres If you know your normal top-up amount, use it here. Pool evaporation varies significantly around Australia.

Livestock

Horses Cattle Sheep / goats

The model uses conservative daily drinking allowances; actual requirements vary with weather, feed, pregnancy/lactation and workload.

Storage preferences

Existing rainwater storage litres Emergency / firefighting reserve

Can you fit a 25,000 L round tank? (approximately 3.9 m diameter × 2.4 m high)

How much rainwater storage do you need?

Where will the tank be?

Roof catchment area

Tell us about the property

How much water will you use?

Showers

Laundry

Garden / lawn

Outdoor taps / cleaning

Car washing

Pool / spa

Livestock

Storage preferences

Running your rainwater model…

Company

Products

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