Siding Calculator: Squares, Panels & Trim
House
typical one-story; measure yours
6 in 12; check your roof
Windows and doors
Default 3' × 5' = 15 sq ft, LP's allowance per window. Measure yours. Source
Default 3' × 7' is our assumption for a door with its trim. Measure yours.
More walls, gables and openings
Siding
- Custom
Exposure, length and carton count of each chip come from the makers’ charts and catalogs. Sources
VSI, WRCLA and CertainTeed add 10 %.
Corners & trim lengths
Piece lengths
Stock lengths from the CertainTeed and Alside catalogs; outside corner posts are also sold 12 ft long.
Results
Add your house length and width, or add a wall.
CladCount counts material only. It does not cover installation, fastening, wind or fire ratings, building codes or permits — follow the manufacturer's installation instructions and your local building department.
How it works
Type the house as a box: its length, width and wall height. Gable ends sit on the two short walls, and their height comes from the roof pitch, the inches the roof rises per foot of run. Anything that is not a plain box goes in as extra walls, extra gables and more window or door sizes.
The walls and gables add up to the gross area; windows and doors are taken off unless you switch that off. The waste percentage is added to the area, and the total is divided by 100 to give squares. Pieces are the area to order divided by what one piece covers, exposure times length, rounded up. Starter strip runs around the base, J-channel around windows, doors and the gable rakes, and every corner gets whole posts.
The house stays in this browser between visits. Every rule and its source is on How we calculate.