Rainwater Collection Calculator
Rainwater Collection Calculation Formulas and Equations
Roof Area (ft2) X Precipitation Amount (in) X 0.623 = Amount Collected (gallons)
Easy Formula to Remember: 1″ of Rain on 1,000 sf Roof Will Yield 623 Gallons
Roof Area (m2) X Precipitation Amount (mm) = Amount Collected (liters)
Other Water Conservation Calculators
An online drip calculator that calculates the amount of waste from your leaky faucets. A service by the American Water Works Association.
A tank performance calculator provided by the Domestic Roofwater Harvesting Programme at the School of Engineering, University of Warwick, England.