Gutter Calculator
Estimate gutter length, stock sections, downspouts, hangers, corners, end caps and material cost for roof eaves.
Default project preview
126 ft
Gutter sections
13
Downspouts
3
Hangers
61
Corners and caps
8
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Input and output guide
What each value means
The labels and units below are part of this calculator’s visible methodology. Replace every default with measurements or product data from the actual project.
Total eave length
Enter this project assumption in ft. The current imperial default is 120 ft.
Extra allowance
Enter this project assumption in %. The current imperial default is 5 %. Minimum: 0. Maximum: 30.
Stock gutter section
Enter this project assumption in ft. The current imperial default is 10 ft.
Maximum downspout spacing
Enter this project assumption in ft. The current imperial default is 40 ft.
Hanger spacing
Enter this project assumption in ft. The current imperial default is 2 ft.
Inside and outside corners
Enter this project assumption in a unitless value. The current imperial default is 4. Minimum: 0.
End caps
Enter this project assumption in a unitless value. The current imperial default is 4. Minimum: 0.
Price per gutter section
Enter this project assumption in a unitless value. The current imperial default is 18. Minimum: 0.
Price per downspout
Enter this project assumption in a unitless value. The current imperial default is 28. Minimum: 0.
Price per corner or end cap
Enter this project assumption in a unitless value. The current imperial default is 8. Minimum: 0.
How to read the outputs
Gutter sections
10 ft each. Default preview: 13.
Downspouts
maximum 40 ft spacing. Default preview: 3.
Hangers
2 ft spacing. Default preview: 61.
Corners and caps
4 corners, 4 end caps. Default preview: 8.
Gutter cost
stock sections. Default preview: $234.00.
Estimated total
sections, downspouts and fittings. Default preview: $382.00.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Order length = eave length × allowance. Sections = round up (order length ÷ stock length). Downspouts = round up (eave length ÷ maximum spacing).
Reviewed project guidance
How to use this estimate in a real project
Last reviewed: July 29, 2026
Use this calculator to estimate gutter lengths, stock sections, outlets and preliminary cost from roof-edge runs. It is a material takeoff and does not establish hydraulic capacity or overflow safety.
Calculation steps
- 1Measure only edges receiving gutters.
- 2Separate straight runs between corners and outlets.
- 3Add cut and lap allowance.
- 4Round to full stock sections and count fittings separately.
Worked numerical example
A roof with 168 ft of gutter edge, 10 ft stock sections and 8% cut allowance requires 19 sections, providing 190 ft of material.
Purchasing and rounding
Gutters, corners, end caps, outlets, hangers and sealants are separate items. Long seamless runs are measured and fabricated differently from sectional systems.
Interpret the result
Extra stock length covers laps, corner cuts and unusable offcuts. Downspout count requires a separate drainage-capacity check.
Page-specific assumptions
- Measured eave lengths are accurate.
- One gutter profile.
- Stock sections use the entered effective length.
- Fittings are counted separately.
Common mistakes
- Using roof perimeter instead of actual gutter edges.
- Ignoring corners and end caps.
- Rounding section count down.
- Assuming material length proves drainage capacity.
Primary and technical references
BuildMeter provides planning estimates, not engineering, architectural, electrical, mechanical, plumbing, permit or code approval. Review the methodology and verify final decisions with product documentation and qualified professionals.
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Gutter Calculator questions
How far apart should downspouts be?+
Spacing depends on rainfall, roof area and gutter capacity. The entered spacing is a planning input, not a drainage design.
How close should gutter hangers be?+
Manufacturer guidance and snow loads control spacing. Many systems use closer spacing in severe climates.
Does this calculate elbows and extensions?+
No. Downspout routing, elbows, outlets and drainage extensions require a site-specific count.