How Much Siding Do I Need?
Siding quantity is wall area converted to squares, with waste added. The trick is measuring the walls right and subtracting the openings.
Measure the walls
Add up the area of every wall (height × width), including gable triangles (½ × base × height). Subtract large windows and doors, but keep waste high near openings because of cuts. Divide by 100 to get squares.
Add waste by profile
Lap siding, board-and-batten and shakes waste differently, and gables and corners increase cuts. Budget 10–15%. The siding calculator converts area to squares and applies the waste automatically.
FAQ
How do I calculate squares of siding?
Total wall area in square feet divided by 100 equals squares. Add 10–15% waste for cuts, gables and corners.
Do I subtract windows and doors?
Subtract large openings, but keep extra waste around them since siding is cut and fitted at every opening.