Skip to content
SARZAMEEN BuyRentAgentsBlog

Rainwater Harvesting Calculator

Enter the roof area and your yearly rainfall to estimate how much water you can store.

Enter your details

mm
Look up your city. Quetta is roughly 250 mm.
litres

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.

    Related tools

    Septic Tank Size CalculatorEstimate the septic tank volume and plan size for a house. Site Expense TrackerRecord construction expenses, compare them to your budget and export to a spreadsheet. Home Loan EMI CalculatorMonthly instalment, total interest and yearly balance for a home or construction loan. Generator Size CalculatorChoose a generator size in kVA from your load and largest motor.