Gutter Calculator
Estimate gutter length, downspouts and end caps.
Gutter length equals the total run of the eaves you are protecting, so measure each roof edge and add the measurements together. Allow one downspout for every 30–40 feet of gutter or every 600–800 sq ft of drained roof. Also include one hanger every 24–32 inches, along with end caps and inside and outside corners. Enter your eave lengths for a full parts list.
Gutter length
60
linear ft
Downspouts
2
1 per 35 ft
Corners + end caps
6
4 corners + 2 caps
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Recommended tools & materials
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Roofing Nailer
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How does the gutter calculator work?
Gutter length equals the roof perimeter carrying water. Add one downspout for every ~35 linear feet, plus two end caps and one connector per corner.
Which guide explains this in more depth?
- Panel roofs waste differently from shingles: ribs, hips and valleys all change the number you order. Read the metal roofing calculator waste factor guide for the full worked example.
What else do people ask about this calculator?
How many downspouts do I need?
One per ~35 ft of gutter is a common rule; heavy-rain regions or steep roofs may need one per 20 ft.
What size gutter for a house?
5 in K-style is standard residential; 6 in is used for large or steep roofs and areas with heavy rainfall.
Which related calculators should I use next?
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