Rainwater Harvest Volume
Enter roof area, rainfall depth, and system efficiency to estimate how much water can be harvested. Results are given in cubic meters.
Estimates only; consult local guidelines for system design.
Examples
- 50 m² roof, 20 mm rain, 80% efficiency ⇒ 0.8 m³
- 120 m² roof, 10 mm rain, 75% efficiency ⇒ 0.9 m³
FAQ
Why divide by 1000?
It converts the result from liters to cubic meters.
What affects collection efficiency?
Roof surface, filters, and storage losses can reduce efficiency.
Can I use rainfall in inches?
Yes, convert inches to millimeters before using the calculator.
Additional Information
- 1 mm of rain on 1 m² yields roughly 1 liter of water before efficiency losses.
- Actual collection varies with roof material and gutter design.