Rainwater Harvesting Calculator

About this tool

Calculate annual rainfall collection and tank sizing for Australian homes using BOM state averages. MyCalcTools calculators are designed for quick everyday estimates with clear inputs, instant results and no account required. Results are provided for general information and planning, not as professional financial, medical, legal or trade advice.

How to use it

1. Enter the values requested in the calculator fields.
2. Choose the option that best matches your situation, unit or goal.
3. Press the calculate button and review the result summary.
4. Adjust your inputs to compare different scenarios.

Common use cases

• Checking a quick estimate before making a decision.
• Comparing two or more everyday scenarios side by side.
• Planning budgets, meals, projects, dates or personal routines.
• Double-checking manual calculations with a simple online reference.