Rainwater Collection Calculator
Estimate collectable rainwater from roof area, rainfall and runoff coefficient.
Calculator
Result
About this calculator
Estimate collectable rainwater from roof area, rainfall and runoff coefficient.
Enter valid values, choose the units you need, then select Calculate. Results are computed in your browser.
How to use this calculator
What to enter
Enter or select the following as requested: Roof area; Rainfall; Runoff coefficient. Follow the units, valid ranges, examples, and options displayed beside each field.
What the result means
The weather-related output is calculated from the environmental measurements and conditions entered. Check units, elevation, location, reference conditions, and the formula assumptions; actual conditions can change quickly.
When to use it
Use this for educational estimates or preliminary planning. For immediate safety, travel, or aviation decisions, consult current official weather information and applicable procedures.