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 18 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

    Plot Coverage and Setback CalculatorFind the buildable footprint after setbacks and the maximum ground coverage. Quotation GeneratorBuild a clean contractor quotation with items, tax and discount, then print or save as PDF. Manpower PlannerFind how many workers you need to finish a job in your target number of days. Septic Tank Size CalculatorEstimate the septic tank volume and plan size for a house.