Your files stay on your device Rainwater harvesting calculator Estimate monthly rainwater yield from your roof area and rainfall with a runoff coefficient, then size a tank against daily demand. Enter a roof area, twelve rainfall values, and a daily use. The collection sum is roof footprint times rainfall times runoff coefficient, one millimetre over one square metre giving one litre. The monthly balance is deliberately simple: it spreads demand evenly and ignores drought sequences longer than a year, pump placement, and plumbing losses beyond the coefficient. It is a sizing estimate, not an irrigation design. Options More unit & math tools - Unit converter (/converters/units) - Aspect ratio and DPI (/converters/aspect-ratio) All unit & math tools (/converters) Was this tool useful? YesNo Canonical HTML: https://nutter.tools/converters/rainwater-harvesting-calculator Markdown version: https://nutter.tools/converters/rainwater-harvesting-calculator.md Plain-text version: https://nutter.tools/converters/rainwater-harvesting-calculator.txt Agent index: https://nutter.tools/llms.txt