The calculator cannot account for complex shapes based on a measurement of square footage alone.
Formula to find square footage of a roof.
So keeping with our roof pitch of 4 this gives us 1 9.
Add 1 then take the square root.
Measure the length and width of every roof plane or surface.
A gable roof and a hip roof of the same length and slope will have identical areas.
Include dormers the small outjuttings over attic.
L h 2 area calculating an area of a triangle when estimating a roof.
Things you will need steel tape measure.
So if you divide your answer of a product of length times height by two you will get the area of a triangle.
Steep roofs measure your house at ground level then add in the roof s overhang for greater accuracy.
In cases where a roof has a complex shape such as in the image to the right measuring the dimensions and areas of each part of the roof to calculate total area will result in a more accurate measurement of area.
If your number is 1 3 squared would yield 1 9 after that add 1 to your number.
For example if your roof s pitch is 4 in 12 you would divide 4 by 12.
Calculate each plane separately.
Gable or hip roof.
Multiply by the square.
Next square your result.
The length l times the height h of a triangle is twice its area a2.
Calculating the area true once you have your roof s pitch divide the number by 12.
1 9 1.
Enter roof dimensions below for your roof in feet or slope as inches rise per foot if you enter only l 1 w 1 h 1 the result will be the area of a single straight gable roof.
Multiply the number of roofing squares for a medium pitch roof by 1 12 to 1 25 or by 1 3 to 1 42 for a high pitch roof to get the square roof area.
1 roof square 100 square feet.
How to calculate square feet of a roof step 1.