One rule of thumb for sizing downspouts and gutters is 1 in.2 of downspout cross section for each 100 ft.2 of covered area to be drained, and a gutter diameter 1.5 in. larger than the downspout diameter.
One rule of thumb for sizing downspouts and gutters is 1 in.2 of downspout cross section foreach 100 ft.2 of covered area to be drained, and a gutter diameter 1.5 in. larger than the downspout diameter.