Siding Calculator
Net wall area subtracts openings. Squares with waste equal (area / 100) times (1 + waste/100). Optional exposure and piece length sketch courses and pieces. Estimate only, not a permit, code check, or engineered design.
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How to estimate siding
- Enter wall length and height in one unit.
- Enter openings area to subtract and waste from 0 to 40 percent.
- Optionally enter exposure height for courses. If exposure is greater than 0, enter piece length too.
- Read net area, squares with waste, and any course or piece sketch.
Siding square takeoff
Wall face minus openings with optional courses
| Net area | max(0, length × height - openings) |
|---|---|
| Squares with waste | (area / 100) × (1 + waste/100) |
| Courses | ceil(height / exposure) when exposure > 0 |
| Pieces sketch | ceil((length / pieceLength) × courses × (1 + waste/100)) |
| Waste bound | 0 to 40 percent |
| Omitted | Corners, J-channel, and starter strips |
What this siding takeoff covers
One rectangular elevation with typed openings. Board and batten vertical counts sit on board and batten. Paint after siding sits on paint. Insulation behind walls sits on insulation.
How squares and pieces are computed
area = max(0, length × height - openings). squares = (area / 100) × (1 + waste/100). If exposure is greater than 0, courses = ceil(height / exposure) and pieces use pieceLength across each course with waste.
Vinyl, fiber cement, and exposure
Exposure is the visible reveal per course. Fiber cement and vinyl publish different piece lengths. Trim and corners are separate SKUs. Drywall interiors sit on drywall.
Use cases
A 40 by 10 wall minus 60 sq ft of openings at 10% waste. Adding 7 in exposure and 12 ft pieces for a course sketch. Not a sealed elevation.
Limits
No automatic gable triangle and no corner post length. Estimate only, not a permit, code check, or engineered design. See the disclaimer.