To do this simply convert the rise and run as a fraction to a decimal form eg.
Roof pitch angle table.
Low slope roofs are from 0 to 3 12 in pitch.
On blue prints architects engineers usually display the pitch of a roof in the format shown on the image where number 4 represents a rise and number 12 represents a length.
Other than the 45 roof slope which is 12 in 12 none of the standard roof pitches 5 in 12 6 in 12 etc are equal to a whole degree.
Find the inverse tangent of the pitch to find the angle in degrees.
Usually they come in the form of a roof pitch diagram chart but other times it will be presented to you in a conversion format.
To find the angle of a roof in degrees convert the pitch to a slope then convert to degrees by finding the arc tangent of the slope.
Notes to the table above.
First convert the pitch to a slope.
Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof.
That s your roof pitch multiplier.
If asphalt shingles are to be installed on a low slope roof special steps are required to avoid short roof life and roof leaks.
You can assess this in two ways either as the roof pitch angles which the rafters make with the horizontal or the proportion between the run and the rise of the roof.
For help converting any slope from one way of expressing it to another see roof slope expressed as rise.
In essence a roof pitch chart is provided as a rough guide usually by a roofing company to help you see what the average roof pitches tend to be.
Roof pitch degree table.
Use the diagrams on this page as a reference when inputting rise and run and while interpreting the calculated results.
Enter any pitch or fraction of pitch to find angle.
Some sources consider low slope to include 3 12 pitch roofs.
Roof online staff last updated july 10 2020 the following table shows the roof pitch rise in run equivalents for all roof slopes in degrees from 1 to 72.
Divide the first part of the ratio by 12 to work out the pitch.
To convert between american roofing ratios and pitch degrees follow these steps.
Often you express roof pitch as the ratio between the rise and the run in the form of x 12.
Enter any angle or fraction of angle to find pitch.
If you know the roof pitch in degrees find the secant of the slope using a scientific calculator.
For example if the roof pitch is 45 then sec 45 1 414213.
This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees.
Run degrees and percentage.
45 this is our pitch calculator which will convert pitch to angle or angle to pitch for half degree roof slope calculations.
A 12 12 pitch roof has a pitch angle of 45.
