Formula For Figuring Out Roof Pitch

The angle or pitch of a roof is calculated by the number of inches it rises vertically for every 12 inches it extends horizontally.

Formula for figuring out roof pitch.

Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio. If you know the angle of the roof in degrees you can find the roof pitch by converting the angle in degrees to a slope then finding the rise by multiplying the slope by 12. Find out how to calculate roof pitch on an existing roof. This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares.

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. Depending whether the roof area is measured horizontally possibly from a drawing or photograph a correction factor is necessary to determine the actual area of the roof. Generally roof pitch is calculated from the same formula that describes a right triangle. Pitch tan angle use this when you express the angle of the roof pitch in degrees what is the standard pitch of a roof.

You can use the following equations to find the length of the rafter and the slope. A 12 in 12 pitch is a steep 45 degree angle roof. How to calculate roof pitch. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length.

Given pitch and a horizontal area measurement multiply the horizontal area by a correction factor corresponding to pitch provided in the table below to determine the actual area of the roof to be used in the roofing material calculator. Image 1 12 to 12 12. Use our calculator to convert the roof angle to pitch if using an angle finder. Includes result for hip valley factor slope factor and the roof slope in degrees.

A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally. Rise run pitch where pitch is expressed in percent. Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement.

See the image below for more explanation on rise run and pitch. To accurately calculate the area of your roof you must first determine its slope or pitch. Roof pitch calculator results explained slope the slope of a roof is represented as x 12 where x is the number of inches in rise for every 12 inches of run. First find the slope by finding the tangent of the degrees eg.

For example a roof that rises 6 inches for every 12 inches of horizontal run has a 6 in 12 pitch.