Downspout Extension Calculator
Size downspout extensions for drainage
sq ft
in/hr
ft
公式
Flow = Roof Area × Rainfall × 0.623 / 96
Calculate water flow from roof to size downspout extensions.
示例
500 sq ft roof, 2 in/hr rain
~6.5 GPM flow rate.
常见问题
关于 Downspout Extension
Size downspout extensions for proper drainage away from foundations.