Find the pitch of any bastard pitch rafter with incredible ease and accuracy with the free Builder Fraction Calculator app.
Learn how to determine the roof pitch equivalent for any known rise and known run with the workshop below. This way you can use a framing square to get more precise cuts on rafters and other framing components.
Install now:
Open app
Click on menu in the top left.
Select Diagonal
Click on diagonal at the top.
The Rise
Enter the rise and click equals.
The Run
Enter the run and click equals.
Results
The rafter pitch is 4 / 12.