Rainwater Harvest Calculator
Use the free online Rainwater Harvest Calculator tool. Fast, private and easy to use — runs entirely in your browser. Part of our Ecology Calculators collection.
Driving Carbon Footprint Calculator
Estimate the CO2 emissions of a car journey from distance and fuel economy.
Tree CO2 Offset Calculator
Find how many trees it takes to absorb a given amount of CO2 each year.
Rainwater Harvest Calculator
Estimate how much rainwater a roof can collect from its area and the rainfall.
LED Energy Savings Calculator
See the yearly energy and money you save by switching a bulb to LED.
Paper Savings Calculator
Translate paper you avoid printing into trees and CO2 saved.
Flight Emissions Calculator
Estimate the carbon emissions of a flight per passenger and in total.
Solar Panel Output Calculator
Estimate the yearly electricity and value a solar array produces where you live.
Compost Ratio Calculator
Balance your compost pile toward the ideal carbon-to-nitrogen ratio of about 30:1.
Frequently Asked Questions
Is the Rainwater Harvest Calculator free to use?
Yes. The Rainwater Harvest Calculator is completely free with no sign-up, no limits and no watermarks. You can use it as many times as you like.
Is the Rainwater Harvest Calculator safe and private?
Absolutely. The Rainwater Harvest Calculator runs entirely in your browser, so your data never leaves your device and nothing is uploaded to a server.
Do I need to install anything to use the Rainwater Harvest Calculator?
No installation is needed. The Rainwater Harvest Calculator works instantly online in any modern browser on desktop, tablet or mobile.
Does the Rainwater Harvest Calculator work on mobile phones?
Yes. The Rainwater Harvest Calculator is fully responsive and works smoothly on iPhone, Android and any other device.