Article: Roofline Calculator
Roofline Calculator
Peak & track cut calculator
Enter your roof slope. Every cut on the gable — the peak cap and all three lighting-track pieces — comes from that one angle. Each result gives you the speed-square mark and the miter-saw setting.
Roof slope
Pitch 6/12 · peak opens to 126.9°
How it sits on the gable
Peak cap — both top edges
2 cutsThe two edges meet to form the 126.9° peak. Mark θ off the level (bottom) edge with the speed square. Bottom edge of the cap is a plain square cut where the center track butts under it.
Center track — both ends
2 cutsMark θ/2 off the freshly squared end. This is a small angle — the same number goes straight on the saw, no flipping.
Down-slope tracks — top ends (L & R)
2 cutsSame θ/2 as the center track — they're the mating halves of the joint. Bottom ends (at the eave, or any splice down the run) are square cuts.
Looking straight down at the saw — fence across the top, blade swinging in the flat plane:
Piece shapes — before & after the cut
Each piece as a flat blank, then the finished shape. The peak cap loses its two top corners; the center track is beveled on both ends; the down-slope track is cut only at the top, square at the base.
180 − 2θ · peak edge θ (saw 90 − θ) · track miters θ/2
