800 multiplied by 1 16.
Formula roof pitch multiplier.
The formula for the roof pitch multiplier comes from the famous pythagorean theorem.
48 10 4 8.
That gives you 5 590 square feet which is the actual area of the surface of the roof.
Now divide the rise by the multiplier to get the pitch eg.
Calculate the rafter length substituting these values into the following formula.
Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m.
Use our roof pitch calculator to find the pitch of your roof.
And for a roof with a slope of 6 12 that number 1 118 is your roof slope multiplier.
Take the area of the roof s footprint say it s 5 000 square feet and multiply 5 000 by 1 118.
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.
If the home measures 20 x 40 and has a 7 12 roof then to calculate the slope of the roof follow these steps.
Steep roofs measure your house at ground level then add in the roof s overhang for greater accuracy.
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.
Step 1 multiply 20 and 40 which equals 800.
100 1 054 105 4ft2.
Calculate the roof pitch as the proportion of rise and run.
Let s say it is equal to 1 5 m.
The calculator above can handle much of this math.
The pitch of this roof is 4 8 12.
Step 3 multiply step 1 and step 2 i e.
Image 1 12 to 12 12 roof pitch 7 12 pitch.
Roof pitch degree table.
For example a 4 12 pitch roof that is 100 square feet.
Use the following formula which also describes a right triangle.
Measure the rise of your roof.
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.
Here are the equations you may use to solve for the length of the slope and the rafter.
Step 2 find the value of 7 12 from the roof slope multiplier table which is 1 16.
You can also calculate roof pitch even without using a roof slope calculator.
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.
Next multiply the footprint of the roof by the multiplier below for your roof pitch to find the overall roof area.
Now solving for c in the equation above gives.
Pitch rise run 1 5 6 25.
