Does anyone know the math formula to convert the angle of a roof in degrees to X in 12 pitch?
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Degrees to Pitch conversion
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Re: Degrees to Pitch conversion
Originally posted by Barry Dennis View PostDoes anyone know the math formula to convert the angle of a roof in degrees to X in 12 pitch?
Barry,
Using a Scientic calculator or Construction Master Calculator. Press the Tan button for any given degree on the plans and multiply by 12 and that will be your pitch.
A Construction Calculator is the easiest one to use.
If you were given a 22.62° pitch on a set of plans, you can this.
22.62 [Pitch] [Pitch] Returns 5 (5/12 is your pitch)
If you have a scientific calculator you can do this.
22.62 [Tan] x 12 = 5 (5/12 is your pitch)
45 [Tan] x 12 = 12 (12/12 is your pitch)Joe Carola
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Re: Degrees to Pitch conversion
Originally posted by Kris M View PostDivide the rise by the run and take inverse tangent of that and it will spit out the degrees.
Kris M.
That's only good if your given the rise. I've had some plans that don't give you the pitch or rise , they just give you the degrees of a roof.Last edited by Joe Carola; 10292006, 07:49 AM.Joe Carola
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Re: Degrees to Pitch conversion
You could just look on the speed square. The pitches & angles are listed on the square & in the book that comes with it.Two roads diverged in a narrow wood. I took the path less traveled.
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Re: Degrees to Pitch conversion
Barry,
Just to give you an example of how you can use Construction Master Trig Calculator.
If you were give a pitch of 22.62° on a set of plans and your common rafter run was 16’ for example without a ridge deduction, you can do this:
Using a Construction Master with Trig:
22.62 [Pitch]
16 [Feet] [Run]
[Diagonal] = 17’ 4” (Common Rafter Length)
Or you can do this:
16 [Feet] [÷] 22.62 [Cosine] = 17’4” (Common Rafter Length)Joe Carola
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Re: Degrees to Pitch conversion
Thanks Everyone, I do remodel projects and run into some oddball pitches so I use a Stabilla electronic level which give me the degrees. I've used the speed square to convert to pitch, but if the roof is an oddball, I need to guess at the pitch (sometimes I need to hit an existing height). I use the stepoff method to layout rafters.
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Re: Degrees to Pitch conversion
Barry, if you are given only the measurement in degrees, since the tangent of an angle is the rise/run you can use this series to solve for Tangent of an Angle.
Be sure you multiply the value of the angle (x in the formula) in degrees by pi/180 to convert it to radians before substituting.
It's a good formula to know if you don't have a calculator but keep a box of pencils and a ream of paper handy ...
Originally posted by Barry DennisDoes anyone know the math formula to convert the angle of a roof in degrees to X in 12 pitch?Last edited by Joe Bartok; 11072006, 04:20 PM."I cannot teach anyone anything; I can only make them think."  Socrates
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