Rainfall Calculator
Water Catchment Calculator
About
Calculate potential rainwater harvest volume and cost savings. This tool helps determine annual water collection capacity based on rainfall and roof area, recommending optimal tank sizes for efficient water storage. It also allows for cost-saving analysis by comparing harvested water to mains water prices.
What's New in Rainfall Calculator
1.3
February 28, 2026
- Updated for the newest devices. - Minor bugs fixed.
Developer apps
FAQ
What is the Rainfall Calculator used for?
Rainfall Calculator is a physics and math tool designed to help users determine the volume of rainwater they can harvest annually, evaluate potential cost savings compared to mains water, and recommend the appropriate size for water storage tanks.
How does Rainfall Calculator determine water volume?
It calculates water volume by multiplying the catchment area (e.g., roof surface area in square meters) by the depth of rain that falls on it (in millimeters). The app provides formula references for clarity.
Can Rainfall Calculator help me save money?
Yes, the app allows you to input the cost of mains or tap water per cubic meter. It then calculates the annual cost savings you could achieve by collecting and using rainwater instead of purchasing tap water.
What is the recommended tank size?
The app recommends a minimum tank size that can store 33% of the 'Annual Rainfall On Your Roof Area'. This ensures you have enough stored water to use while collection is ongoing.
Does Rainfall Calculator support different units?
Yes, the app supports various units for each input, providing flexibility for users worldwide. It also supports calculations up to 16 decimal places for high precision.
Is Rainfall Calculator available on multiple devices?
Rainfall Calculator works seamlessly on both iPhone and iPad. It is designed to be a lightweight and compact app optimized for everyday use on these iOS devices.
Does Rainfall Calculator have ads?
No, Rainfall Calculator is ad-free. The developer has built the app with privacy in mind and aims to provide an uninterrupted user experience.
How often is Rainfall Calculator updated?
The latest version of Rainfall Calculator is 1.3, last updated on February 28, 2026. While specific update frequency isn't detailed, this indicates ongoing support and development.
