How this worksheet works
From separate planes to one checked total
Break a complex roof into rectangular planes. Each row converts horizontal plane dimensions to sloped area with its own pitch, making assumptions reviewable before quantities are combined.
How to use it
- Divide the roof plan into rectangular planes and number them.
- Enter horizontal length, width, and rise-per-12 for each plane you use.
- Calculate, review the row-by-row areas, and apply the overall waste allowance to the combined result.
Useful for
- Mixed-pitch roof takeoffs
- Reviewable plane schedules
- Preparing area totals for downstream material calculators
Assumptions
- Each row is a rectangular horizontal footprint
- Run is normalized to 12 for every row
- One overall waste rate is applied after plane areas are totaled
Limitations
- Triangles, trapezoids, and irregular planes must first be converted to equivalent horizontal area
- Does not deduct openings or add overhangs automatically
- Does not create a cut plan or identify shared edges
Common checks
Questions about this calculator
Can different rows have different pitches?
Yes. Each plane has its own rise-per-12 input and slope factor.
How do I enter a triangular plane?
Calculate its horizontal area separately (base × height ÷ 2), then represent that area with equivalent rectangular dimensions or add it to a separate verified takeoff.