Gutter LF and Downspout Count Takeoff
Gutter footage, downspout count, pipe, and hangers: gutter = eave; downspouts = ceil(roof area / max area per downspout); pipe = downspouts x wall height; hangers = ceil(eave / spacing). 140 LF of eave on a 2,400 sf roof at 800 sf per downspout is 3 downspouts, 30 LF of downspout pipe, and about 70 hangers; a bigger 4,000 sf roof needs 5 downspouts and 50 LF of pipe. The roof area drives the downspouts, the eave drives the gutter and hangers. Distinct from the cross-section sizing in gutter-downspout.
Formula and source
gutter_lf = eave_length_ft; downspouts = ceil(roof_area_sf / max_area_per_downspout_sf); downspout_pipe_lf = downspouts x wall_height_ft; hangers = ceil(eave_length_ft / hanger_spacing_ft).
Gutter takeoff identity by name (gutter runs the eave; downspouts from the roof area over the per-downspout area; pipe and hangers from height and spacing); first-principles arithmetic.
Audience
This tile is built for trades and the adjacent professions in the Carpentry and Construction group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.
Related tools
Posture
Rough Logic answers the math question the working professional asks on the job. The site is a calm, fast, ad-free, account-free, ever-free reference. It does not interpret code. It does not replace the licensed professional. It does not store your inputs. The Authority Having Jurisdiction governs all installations and inspections.