Instruction Manual

Common Rafter
— Pitch Unknown
You’re unsure of the roof Pitch but know both
the Rise; 6 feet 11-1/2 inches and Run; 14 feet 6
inches. Find the common rafter length. Then
solve for the Pitch.
COMMENTS KEYSTROKES
Clear calculator [On/C] [On/C]
Enter Rise 6 [Feet] 11 [Inch]
1 [/] 2 [Rise]
Enter Run 14 [Feet]
6 [Inch] [Run]
Find rafter length [Diag]
Answer: 16 FT 1 IN
Find Pitch [Pitch]
Answer: 5-49/64 IN
Computing the Rise Side
of an Angle
Though not commonly asked for, you can
compute the Rise or Run side of a right angle just
as you would the Diagonal. Here, find the Rise
given a 7-in-12 Pitch and a Run of 11 feet 6
inches:
COMMENTS KEYSTROKES
Clear calculator [On/C] [On/C]
Enter Pitch 7 [Inch] [Pitch]
Enter Run 11 [Feet]
6 [Inch] [Run]
Find Rise [Rise]
Answer: 6 FT 8-1/2 IN
40 — Construction Master III
®