Formula For Figuring Out Roof Pitch

A 12 in 12 pitch is a steep 45 degree angle roof.

Formula for figuring out roof pitch. First find the slope by finding the tangent of the degrees eg. Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. Includes result for hip valley factor slope factor and the roof slope in degrees. 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.

After measuring the slope estimate the roof pitch by dividing the slope by 2 if you have a simple gable roof. Find out how to calculate roof pitch on an existing roof. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. Use our calculator to convert the roof angle to pitch if using an angle finder.

Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio. The angle or pitch of a roof is calculated by the number of inches it rises vertically for every 12 inches it extends horizontally. You can use the following equations to find the length of the rafter and the slope. Pitch tan angle use this when you express the angle of the roof pitch in degrees what is the standard pitch of a roof.

Rise run pitch where pitch is expressed in percent. To accurately calculate the area of your roof you must first determine its slope or pitch. For example a roof that rises 6 inches for every 12 inches of horizontal run has a 6 in 12 pitch. See the image below for more explanation on rise run and pitch.

Generally roof pitch is calculated from the same formula that describes a right triangle. 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. However if you have a more complex roof you may need to calculate pitch section by section. How to calculate roof pitch.

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. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement. Rafter rise run from the pythagorean theorem. 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.

A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally.