Standard symmetric gable vs. half/shed gable — why the same width and pitch give a different area
Same width, same pitch — the gable type changes everything. A symmetric gable’s pitch runs over ½ the span (72 ft², 2 rakes); a shed gable’s runs over the FULL span, so the peak is 2× taller and the area doubles (144 ft², 1 rake).
What this diagram shows
Two gables compared at the same 24-foot width and the same 6:12 pitch. The standard symmetric gable has its peak in the middle, so the pitch acts over only half the span (a 12-foot run) and the peak rises 6 feet; its area is one-half times 24 times 6, or 72 square feet, and it has two sloped rake edges. The half or shed gable is a single slope, so the pitch acts over the full 24-foot span and the peak rises 12 feet — twice as tall; its area is one-half times 24 times 12, or 144 square feet, double the standard gable, and it has only one rake edge. Same width and pitch, but the gable type decides the run, the height, the area, and the number of rake edges.
Gable Area Calculator
Free gable area calculator: get the square footage of a gable end from width and roof pitch or peak height, plus rake trim length and siding waste.
