Formula Roof Pitch Multiplier

A 2 b 2 c 2 where a is the rise of the roof b is the run of the roof and c is the rafter hypotenuse of the triangle with side lengths a and b.

Formula roof pitch multiplier.

Next multiply the footprint of the roof by the multiplier below for your roof pitch to find the overall roof area. The maths behind this number is that it is the square root of rise run 2 1. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot. If the home measures 20 x 40 and has a 7 12 roof then to calculate the slope of the roof follow these steps.

The formula for the roof pitch multiplier comes from the famous pythagorean theorem. 800 multiplied by 1 16. A 12 in 12 pitch is a steep 45 degree angle roof. Once you know the roof slope multiplier for a particular slope you can use it to find the actual area of any size sloped roof with the same slope.

Multiply 20 and 40 which equals 800. Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. Image 1 12 to 12 12 roof pitch 7 12 pitch. See the image below for more explanation on rise run and pitch.

Find the value of 7 12 from the roof slope multiplier table which is 1 16. For example a 4 12 pitch roof that is 100 square feet. 100 1 054 105 4ft2. Now solving for c in the equation above gives.

Roof pitch degree table. A roof pitch multiplier also called a roof pitch factor is a number that is multiplied by the area covered by a sloped roof to produce the area of the actual surface of the roof. So in this case for every 12 inches the roof goes across horizontally b while rising 6 inches a there s actually 13 416 inches of roof c. Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio.

A roof pitch multiplier also known as a roof pitch factor is a number that when multiplied by the area covered by a sloped roof gives the actual area of the roof. For roof slopes expressed as x in 12 rise in run the roof pitch multiplier is determined by finding the square root of rise run 1. The roof pitch is important in determining the appropriate installation method and how much roofing material will be needed. Roof pitch is used to describe the slope or angle of the roof.

Use our roof pitch calculator to find the pitch of your roof. Although there s isn t any standard pitch of a roof used on all kinds of sloped roofs you can determine the range of pitches by using a roof angle calculator and by considering factors like the local climate and roofing materials.