How it works
Fill in the 2 fields above and Rainfall Collection Calculator calculates the result instantly, recalculating as you change any value. The math runs locally in your browser — nothing is sent to a server.
Examples
- Catchment area 1000 sq ft, Rainfall 1 in → Water collected: 623 gallons
Frequently asked questions
How do I use the Rainfall Collection Calculator?
Enter your values in the 2 input fields and the result is calculated automatically as you type. Change any value to see the numbers update instantly.
Is my data private?
Yes. The Rainfall Collection Calculator runs entirely in your browser. Nothing you enter is uploaded, saved to a server, or shared — it never leaves your device.
Is the Rainfall Collection Calculator free?
Yes, it is completely free with no sign-up, no limits and no watermarks. Like every tool on weather & nature and the rest of the platform, you can use it as often as you like.
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