Siding Calculator
Calculate how many squares of siding you need for a house exterior. Works for vinyl, fiber cement, wood lap, and panel siding. Get material quantities for walls, gables, and complete siding estimates.
Formula & Reference
| Variable | Formula | Units |
|---|---|---|
| Siding Calculator | Squares = Wall Area / 100 sq ft (1 square = 100 sq ft) | squares + pieces |
Step-by-Step Examples
40x28 ft house (136 ft perim), 9 ft walls, 2 gables (80 sq ft each), 150 sq ft openings, 10% waste.
- Wall area = 136 x 9 = 1,224 sq ft
- Gables = 80 x 2 = 160 sq ft
- Openings = 150 sq ft
- Net = (1,224+160-150) x 1.10 = 1,358.6 sq ft = 13.6 squares
160 ft perimeter, 18 ft walls (two stories), 4 gables (120 sq ft each), 300 sq ft openings.
- Wall area = 160 x 18 = 2,880 sq ft
- Gables = 480 sq ft | Openings = 300 sq ft
- Net x 1.10 = 3,366 sq ft = 33.7 squares
60 ft perimeter, 10 ft walls, 1 gable (60 sq ft), 2 garage doors (144 sq ft).
- Wall area = 600 sq ft + 60 gable - 144 openings = 516 sq ft
- x 1.10 = 567.6 sq ft = 5.7 squares
Real-World Applications
Common Mistakes to Avoid
Windows and doors don't get sided. Forgetting to subtract them wastes 10-20% of your siding budget on material you don't need.
Gable triangles have less area than their bounding rectangle. Calculate each gable as 1/2 x base x height, not as a rectangle.
Vinyl and fiber cement require 10-12% waste. Diagonal or complex patterns need 15-20%. Stone or brick veneer requires separate calculation.