Calculate Box Gutter Size

See photos below most residential gutters will measure approximately 5 inches across the top with the actual opening being approximately 4 5 inches.

Calculate box gutter size.

If a roof s various drainage areas call for different size gutters go for the biggest one k style. Then use the chart below to see what size gutter you need. Sizes the depth shown of the box gutter is the depth at the upstream end. We recommend using this calculator as a basic tool to begin determining the requirements for your drainage system however all information should be verified by.

Measure your gutter across the top from the back where the gutter meets the home to the outer edge. Sides must be vertical. Northclad gutter size requirement calculator this calculator uses current data to calculate the required size of gutter as well as number and size of downspouts based on your input. Box gutters must be straight no bends.

6 inch 7 960 square feet. 5 inch 5 520 square feet. Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed. Must have a constant slope between 1 40 and 1 200.

Size downspouts to fit the gutter. Down pipe must be vertical from sump not to the side minimum sump length is 400mm. Doubling the number of downspouts halves the required capacity for each. A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour.

Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.