Roof Pitch Conversion Chart

If this isn t practical then perform the same measurement on the underside of the roof.

Roof pitch conversion chart.

On blue prints architects engineers usually display the pitch of a roof in the format shown on the image where number 4 represents a rise and number 12 represents a length. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. You can also calculate roof pitch even without using a roof slope calculator. 48 10 4 8.

Here are the equations you may use to solve for the length of the slope and the rafter. Rafter rise run this formula is from the pythagorean theorem. The pitch of this roof is 4 8 12. Use the following formula which also describes a right triangle.

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. Since pitch is the rise over a 12 inch run divide the run by 12 to get the multiplier in this case 120 12 10. What is a roof pitch chart. The combination of two numbers are used to display or show the roof pitch.

Now divide the rise by the multiplier to get the pitch eg. The calculator above can handle much of this math. In essence a roof pitch chart is provided as a rough guide usually by a roofing company to help you see what the average roof pitches tend to be.