Multiply the length and width of each square or rectangle shaped plane.
How to measure sq feet of roof.
Include dormers the small outjuttings over attic.
If the house has an irregular shape measure each part separately figure the separate areas and add them together.
Because each 100 square feet of roof is one.
Measure the length and width of every roof plane or surface.
Convert the area to roofing squares.
Check that your footage measurements are within this range so you can start off on the right foot.
Simply input the surface area of the roof choose from one of the available options and you will get your first roofing estimate.
If its pitch is 6 in 12 a pitch multiplier of 1 12 multiplying 1 152 sq ft 107 0 m 2 by 1 12 would give you an overall square footage of 1 290 square feet 120 m 2.
Next you will need to use a roofing materials calculator.
This nominal square footage amount is then multiplied by a factor associated with the roof s pitch.
As an example if your overhang is 12 inches you ll add 2 feet to the overall length and 2 feet to the overall width of the house.
The calculator cannot account for complex shapes based on a measurement of square footage alone.
Measure your house at ground level then add in the roof s overhang for greater accuracy.
Calculate each plane separately.
How to calculate square feet of a roof step 1.