Gutter Linear Footage & Miter Estimator

The industry standard is one 2x3 downspout for every 20-30 feet of gutter run. However, if you are installing 6-inch gutters on a steep-slope roof, you can often push spacing to 40 feet if you use 3x4 oversized downspouts to handle the increased water velocity.

If the roof pitch is 8/12 or steeper, or if the roof surface area feeding into a single run exceeds 1,500 sq. ft., 5-inch gutters will likely overshoot during heavy downpours. Specifying 6-inch gutters in your bid demonstrates technical superiority and prevents future warranty calls for foundation erosion.