Rainfall Volume Calculator

Calculate Rainwater Collection Volume

Calculate the volume of water collected from rainfall based on catchment area and rainfall amount for rainwater harvesting.

Catchment Parameters

m²

Roof or catchment area

mm

Total rainfall depth

Formula

Volume = Area × Rainfall

Assumes 100% collection efficiency

Efficiency Note

Actual collection is typically 75-90% due to losses from evaporation, spillage, and first flush diversion.

About Rainwater Harvesting

Rainwater harvesting collects and stores rainwater from roofs and other surfaces for later use, reducing dependence on municipal water supplies.

  • Reduces water bills
  • Provides backup water supply
  • Reduces stormwater runoff

Applications

  • Residential rainwater harvesting
  • Agricultural irrigation planning
  • Commercial building water management
  • Tank sizing and design
  • Water conservation planning