How To Estimate Roof Pitch

You can use the following equations to find the length of the rafter and the slope.

How to estimate roof pitch.

How to calculate roof 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. Then in the attic place the end of the level against the bottom of a roof rafter and hold it perfectly level. 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. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run. A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally. First measure 12 inches from one end of the level and make a mark.

Here are a couple examples. How roof pitch is calculated to accurately calculate the area of your roof you must first determine its slope or pitch. If you do need to calculate the pitch an estimate or shortcut is usually more practical than measuring the roof s overall dimensions. This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares.

It is often compared to slope but is not exactly the same. As aforementioned there is no standard pitch of a roof. Express roof pitch as the ratio of the amount of the vertical rise of a roof or rise over the corresponding horizontal distance or run you write the pitch assuming a run of 12 inches thus the ratio would describe how much a roof rises for each foot of the run. You ll need a level that is 12 or longer and a tape measure.

For a simple gable roof the span wall to wall will be twice the size of the run wall to ridge horizontally. Rafter rise run from the pythagorean theorem. To measure the roof pitch you ll need an 18 or 24 inch level a tape measure and a pencil. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches.

Generally roof pitch is calculated from the same formula that describes a right triangle.