Free tool
Siding calculator
Siding squares with gables included and openings deducted, plus starter and corners.
Inputs
Estimated materials
- Siding squares (with waste)
- 15.8 squares
- Net wall area
- 1,434 SF
- Gable area
- 210 SF
- Starter strip
- 160 LF
- Outside corner posts (10 ft)
- 4 posts
- J-channel around openings (approx.)
- 192 LF
Deducts ~18 SF per typical door or window. One siding square covers 100 SF. Panel profiles and exposure vary; confirm coverage per box with the manufacturer. Estimate — verify before ordering.
Frequently asked
- How do I calculate how much siding I need?
- Multiply the house perimeter by wall height, add each gable (½ × width × rise), subtract doors and windows, add 10% waste, and divide by 100 to get squares.
- What is a square of siding?
- A square is 100 SF of wall coverage — the standard unit for ordering vinyl, fiber cement, and other lap siding.
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