Rainwater Harvesting Calculator
Estimate the amount of rainwater you can collect!
What is a Rainwater Collection Calculator?
A Rainwater Collection Calculator is an online tool that helps estimate how much rainwater can be harvested from a surface, usually a roof, based on factors like:
✅ Roof area (sq. meters or sq. feet)
✅ Annual or monthly rainfall (mm or inches)
✅ Collection efficiency (%)
How It Works:
The calculator uses the formula:
Collected Water=Roof Area×Rainfall×Efficiency Factor×0.001\text{Collected Water} = \text{Roof Area} \times \text{Rainfall} \times \text{Efficiency Factor} \times 0.001Collected Water=Roof Area×Rainfall×Efficiency Factor×0.001
Example:
If you have a 100 sq. meter roof, with 1000 mm of rainfall per year, and 85% collection efficiency, the potential harvested water would be:
100×1000×0.85×0.001=85 cubic meters of water annually100 \times 1000 \times 0.85 \times 0.001 = 85 \text{ cubic meters of water annually}100×1000×0.85×0.001=85 cubic meters of water annually