Rainfall to Volume Calculator
Shows how much water a depth of rain really is on a given area.
Volume of rain
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Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
Litres — L
US gallons — gal
Imperial gallons — gal
Weight of water —
The formula
volume = rainfall depth × area
One millimetre on one square metre is one litre, and one millimetre on one hectare is 10 m³.
What to watch out for
Not all of it reaches the roots. On a field, some runs off or evaporates, more so in a heavy storm or on dry baked ground. To size a tank for a roof, use the rainwater harvesting calculator.
Frequently Asked Questions
How much water is 1 inch of rain on an acre?
27,154 US gallons, or 102.8 m³.
How much water is 1 mm of rain per hectare?
10 m³, or 10,000 litres.