Rainwater Harvesting Calculator
Enter the roof area and your yearly rainfall to estimate how much water you can store.
Pakistan Lands Tools | Rainwater Harvesting Calculator
Estimate generated 17 Oct 2026 | https://property.candletrack.pro/public/buildcraft/tool/rainwater-harvesting-calculator
Results
Enter your values and press Calculate. Results will appear here and update as you change inputs.
Rainfall varies from year to year. Treat harvested water before drinking.
How this calculator works
- Water = roof area (m²) × rainfall (mm) × runoff factor × 0.9 (first-flush loss).
- Runoff factor: concrete 0.8, tiles 0.75, metal 0.9.
Frequently asked questions
Not without filtering and disinfecting. It is mainly used for gardens, cleaning and flushing.
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