Select your roof pitch. Get the exact bevel angle to set on your circular saw or Speed Square for plumb cuts, level cuts, and hip/valley cheek cuts.
Roof Pitch
A plumb cut is a cut that is perfectly vertical when the rafter is installed in position. It is made at the ridge (top end) and at the heel of the birdsmouth. The angle equals the roof's pitch angle — for a 6:12 pitch that is 26.6°.
A level cut (or seat cut) is horizontal when the rafter is in place — it sits flat on the wall plate. The level cut angle is always 90° minus the plumb cut angle.
On a Speed Square: hold it against the rafter edge, pivot until the "COMMON" scale reads your pitch (e.g., 6), and scribe the plumb line. Most Speed Squares also have a "HIP/VAL" scale for hip and valley rafters.
For a circular saw: set the bevel to the plumb cut angle from vertical (or equivalently, tilt the blade to the complementary angle from horizontal). Mark the cut line plumb on the rafter, then follow it with the bevel set.
| Pitch | Plumb Cut | Level Cut | Hip/Val Plumb | Hip/Val Level | Slope % | Type |
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