Example slope as angle.
Roof slope degree.
A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof.
To put it in perspective the angle of this slope would be around 30 degrees.
The 45 degree roofs seen on a frame houses are 12 in 12 but roofs can be even steeper consider the mansard roofs introduced by french second empire architects in the middle of the 1800s.
An example for a steep sloped roof is 8 12.
This means that the rise of the slope goes up or down 8 inches for every 12 inches.
Measuring the slope from the rafters.
Some of the most common roof pitch types are conventional slope type roofs designed with pitch ranging from 4 12 to 9 12.
Also see our page quick reference.
Roof pitch is a measurement of a roof s slope expressed as a ratio.
The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7.
The table below shows common roof pitches and the equivalent grade degrees and radians for each.
The following table shows the roof pitch rise in run equivalents for all roof slopes in degrees from 1 to 72.
To see what the degree equivalents are for standard rise in run roof pitches see our page quick reference.
These are utilized in residential applications.
Either way let s see how you can calculate the slope of a roof without using a roof slope calculator.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
See below after the table for directions on how to convert any roof slope from one form to another even roof slopes not shown in the table.
Degrees to roof pitch rise in run to see a table.
Although there is no single standard roof pitch used on all sloped roofs factors such as roofing materials and local climate help to determine the appropriate range of pitches for a given building.
The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches.
Pitched roofs begin with with slopes greater than 3 in 12.
Roof pitches exceeding the level of 9 12 or approximately 37 degrees are termed steep slope roofs.
The following table shows how the same common roof slopes can be expressed using rise in run ratios degrees and percentages.
It s just a little math.
Sangle tan 1 1 m 2 m 26 6.
Access one of the rafters then take the measurement this way.
Roof slope expressed as rise.
Most roof s have a pitch in the 4 12 to 9 12 range.
Mansard roofs with nearly vertical faces can boast a pitch of 20 in 12.
Last updated july 10 2020.
