How to use this calculator
Enter the total linear feet of gutter you need by measuring along the fascia board (the bottom edge of your roof) where gutters will be installed. You can add multiple runs if your roofline has different sections. Then select a gutter size, either 5 inch (standard for most homes) or 6 inch (for steep roofs or heavy rainfall areas).
Next, enter the number of inside corners, outside corners, and downspout locations. The calculator uses these to determine the correct quantities of elbows, end caps, connectors, and hangers. Hangers are spaced every 24 to 36 inches depending on your climate, with closer spacing recommended in areas that experience heavy snow or ice.
The results provide a complete materials list with quantities for every component, plus an optional cost estimate if you enter prices. Use this list when shopping at the home improvement store to ensure you buy everything in one trip and avoid delays during installation.
How to measure for gutters
Measure along the bottom edge of your roof (the fascia board) where gutters will be installed. Measure each straight section separately. Do not include gable ends or areas where no gutter is needed.
Count inside corners (where the roof turns inward, like an L-shaped house) and outside corners (where it turns outward). Note where you want downspouts placed. The rule of thumb is one downspout for every 30 to 40 feet of gutter run.
Frequently asked questions
5 inch vs 6 inch gutters: which do I need?
Standard 5 inch gutters handle most residential roofs. Choose 6 inch gutters if you have a steep roof pitch, large roof area, or live in an area with heavy rainfall. Homes with metal roofs or in the Pacific Northwest often benefit from 6 inch gutters.
How many downspouts do I need?
The general rule is one downspout for every 30 to 40 feet of gutter. Place downspouts at low points where water naturally flows. Each downspout can handle about 600 square feet of roof area. More downspouts mean less water pressure in each one.
Seamless vs sectional gutters?
Seamless gutters are custom-formed on site from a single piece of metal, so they have no joints that can leak. Sectional gutters come in 10 foot pieces and are joined with connectors. Seamless costs more but lasts longer and requires less maintenance.
How often should gutters be replaced?
Aluminum gutters last 20 to 30 years. Copper gutters can last 50 years or more. Signs you need replacement include sagging, pulling away from the house, visible rust or cracks, water pooling at the foundation, and paint peeling on fascia boards.