Siding Calculator
Estimate siding materials for vinyl, wood, fiber cement, or board & batten — with opening deductions and cost.
Need wall sheathing underneath your siding? Calculate plywood sheets for walls with our Plywood Calculator.
Input
Wall Sections
Openings (Windows & Doors)
Result
How It Works
Net Area = Wall Area − Openings. Required = Net × (1 + Waste%). Squares = Required / 100. One "square" = 100 sq ft of siding — the standard unit in the siding industry.
Understanding Siding Calculations
Accurate siding estimation prevents over-ordering (wasted money) or under-ordering (delays and color mismatch on reorders). This calculator handles multiple wall sections, opening deductions, and industry-standard waste factors.
Siding Calculation Formula
In the siding industry, materials are sold by the "square" — 100 square feet of coverage. Always round up to the next whole square when ordering.
How to Estimate Siding Materials
Siding Cost Ranges by Material
- Vinyl siding: $2–$7 per sq ft installed. Most affordable and low-maintenance option.
- Wood siding: $5–$14 per sq ft installed. Natural look but requires regular maintenance (painting/staining every 3–7 years).
- Fiber cement (Hardie): $6–$13 per sq ft installed. Durable, fire-resistant, and pest-proof.
- Board & Batten: $5–$12 per sq ft installed. Popular farmhouse/modern style with alternating wide and narrow boards.
Frequently Asked Questions
How much siding do I need for a 1500 sq ft house?
A typical 1500 sq ft single-story home has about 1,200–1,500 sq ft of exterior wall area (after subtracting windows and doors). With 10% waste, order 1,320–1,650 sq ft or 14–17 squares. Two-story homes of the same footprint have more wall area — about 2,000–2,500 sq ft or 20–25 squares.
What is a "square" in siding?
A square is the standard unit for siding measurement, equal to 100 square feet of wall surface. When you buy siding, it's priced and packaged by the square. For example, a box of vinyl siding typically covers 1 or 2 squares (100 or 200 sq ft).
How much waste should I add for siding?
10% waste is standard for simple rectangular walls with vinyl or fiber cement. Use 15% for wood siding (more cuts and defects), gable ends, or complex shapes. Board & batten may need only 5-10% since cuts are simpler. Always add extra if matching existing siding on a repair.
Should I subtract window and door areas from siding?
Yes — subtract all window and door openings from the gross wall area to get the net area that actually needs siding. This saves significant material on homes with large windows or garage doors. Don't subtract small openings like vents or electrical boxes.
How does gable end siding differ from flat wall siding?
Gable ends are triangular and require angled cuts, which means more waste. Calculate a gable end area as ½ × (gable width × gable height) above the wall top plate. Add 15-20% waste for gable siding because of the many angle cuts and short pieces that can't be reused.