Roof Rise Formula

The total roof rise in the example equals 78 inches.

Roof rise formula.

For example if your tape measure found a 6 inch vertical distance to the 12 inch mark on your level the slope is 6 12 or 6 in 12. Approximately 8 9 16 in 12. Roof slope is also called as roof pitch. It is computed by using the simple roof slope formula.

Write the roof slope as the ratio of rise over run or vertical distance over horizontal distance. In civil engineering the slope is the numerical measure of the steepness of a roof. Use the following formula which also describes a right triangle. 0 713 x 12 8 556.

In the united states slopes are traditionally given with 12 as the second number of the ratio. Giving you a slope of 8 556 in 12 or. In the imperial unit of measurements the slope is expressed with the rise and run. On a 38 degree sloping roof angle t each individual vertical rise of 9 4 y 1 would have a horizontal run x 1 of 12 inches.

Multiply your figure for unit rise by your figure for total run to get the total rise. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. Calculate the roof rise using the figures for unit rise and total run. 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.

You can also calculate roof pitch even without using a roof slope calculator. Rafter rise run this formula is from the pythagorean theorem rise run pitch use this when you express the pitch in percent. Total roof rise or change in elevation for a 38 degree sloping roof angle t with one giant rise or step of 7 8 feet to the center of the attic y 2 would have total a run x 2 of 10 feet. By slope angle formula steepness can be obtained by dividing vertical rise by horizontal span.

If you re not sure what the slope of your roof is and you want to determine that in either degrees or rise in run we recommend this slope finder on amazon. It s very inexpensive and very accurate. A 4 12 is a roof slope that rises by 4 inches for every 12 inches across.