How Do I Calculate The Pitch Of My Roof

How Do I Calculate The Pitch Of My Roof. Rafter² = rise² + run² (from the pythagorean theorem); Pitch = tan (angle), (use this when you express the angle of the roof pitch in degrees) what is the standard pitch of a roof?

It is often compared to slope, but is not exactly the same. There is a formula to measuring the exact pitch of your roof that you do not need to be pythagoras to use. Here’s a better breakdown… 12 x 0.334595319 = 4.015 (round to 4 inches).

To get x, compute $$x=12×{rise \over run}=12×.354=4.2$$ therefore, the pitch of your roof is 4.2/12.

The example to right shows 2 different ways to determine or calculate roof pitch, also called roof slope. After measuring the slope, estimate the roof pitch by dividing the slope by 2 if you have a simple gable roof. Without getting into the specifics of trigonometry, using a calculator the formula is 12 (inches across the top) times the tan (tangent) of 18.5 degrees, which equals 4.0. Simply mark a level at 12″, hold it perfectly level and measure from the roof surface to your 12″ mark, this.