Let s say it is equal to 1 5 m.
Formula for working out roof pitch.
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.
The calculator above can handle much of this math.
Pitch rise run 1 5 6 25.
Roof pitch formula image 1 12 to 12 12 roof pitch 7 12 pitch this is our pitch calculator which will convert pitch to angle or angle to pitch for half degree roof slope calculations.
For many people working out the roof pitch angles can be a bit of a nightmare especially if you are going to do it yourself and try to manage it all on your own.
Calculate the rafter length substituting these values into the following formula.
For a simple gable roof the span wall to wall will be twice the size of the run wall to ridge horizontally.
Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m.
Calculate the roof pitch as the proportion of rise and run.
Naturally this does not go down particularly well without the right tools knowledge and assistance.
For a roof with the ridge above one wall the span is the same as the run.
Here are the equations you may use to solve for the length of the slope and the rafter.
The pitch of this roof is 4 8 12.
The slope is the same as the pitch.
Rafter rise run this formula is from the pythagorean theorem.
Now divide the rise by the multiplier to get the pitch eg.
Use the following formula which also describes a right triangle.