Gutter & Downspout Calculator — ft, cost
How to use this calculator
Enter the total gutter run (eave length), choose gutter size and style, specify the number of downspouts, corners, and section length. The calculator computes all materials needed: gutter sections, downspouts, hangers/brackets, elbows, end caps, and splash blocks.
Rule of thumb — 1 downspout per 35 ft of gutter run. Hangers every 24″ (2 ft). Each downspout needs 2–3 elbows. Standard gutter sections are 10 ft.
Saved Calculations
| Time | Run ft | Sections | DS | Hangers | Elbows | Cost |
|---|
How to Calculate Gutter & Downspout Materials
This calculator estimates all materials needed for a gutter installation: gutter sections, downspouts, hangers/brackets, elbows, end caps, inside/outside corners, and splash blocks. Enter the total eave length, choose your gutter size and style, and specify the number of downspouts.
Formulas
Gutter sections = total run / section length, rounded up. Hangers = total run (in) / spacing + 1. Elbows = downspouts × elbows per DS. Downspout sections = downspouts × ceiling(height / 10 ft).
FAQ
How many downspouts do I need? One downspout per 35 linear feet of gutter is a good rule. Add more for heavy rainfall areas or steep roofs.
What size gutter should I use? 5″ K-style handles most homes. Use 6″ for large roof areas (over 1,500 ft² draining to one gutter run) or heavy rainfall regions.
