You’ve made the decision to install a rainwater tank in your home, but sometimes it is hard to know where to go from there. How do you know what size rainwater tank will best suit your home?

When trying to calculate your rainwater storage needs, there are a few things that you need to consider to help determine what size rainwater tank you require:

  • total water demand
  • roof catchment area
  • rainfall characteristics

We recommend using an online calculator to help you find out what rainwater tank solution would best suit your needs. We have done some research and we have found that these two calculators are very helpful.

Just click on the links below, input the required information and the output will help you figure out the best rainwater tank solution for you.

Sydney Water:


If you know someone who would like some helpful tools in helping them decide what type of tank they need, share this article with them. Or call Sydney Water Tanks and speak to one of our sales representatives who will be able to answer any of your questions or offer you a rainwater storage solution to suit your needs. Call us on 1800 041 111 or email