Use our free Rainfall Calculator to quickly determine the volume of rainwater you can collect from any surface. Ideal for rainwater harvesting systems, planning garden irrigation, or understanding stormwater runoff. Input your area and rainfall depth to get results in liters and US gallons.
Formula:
The core formula for calculating the volume of collected rainwater is:
Volume (Liters) = Area (m²) × Rainfall Depth (mm)
- Area (m²): The surface area collecting the rainfall (e.g., roof, ground).
- Rainfall Depth (mm): The measured depth of rainfall over the collection area.
The calculator automatically handles unit conversions for area (m² or ft²) and rainfall depth (mm or inches) to provide results in Liters and US Gallons.