Siding Calculator: Square Footage, Squares and Cost
| Material | Per sq ft | Your job | Lasts |
|---|---|---|---|
| Vinyl | $6–$12 | $13,998–$27,996 | 20–40 yrs |
| Engineered wood | $9–$16 | $20,997–$37,328 | 20–30 yrs |
| Fiber cement | $10–$20 | $23,330–$46,660 | 30–50 yrs |
| Natural wood | $12–$25 | $27,996–$58,325 | 20–40 yrs |
How the siding maths works
The same wall-area rules our quote widget uses, so the two agree on the same house. Cost ranges are typical national installed prices, not a quote.
- Walls. Perimeter (2 × (length + width)) × storeys × 9 ft.
- Gables. Each gable end is a triangle on the short side: span × rise ÷ 2, with the rise from the roof pitch.
- Openings. Subtract 15% for windows and doors.
- Order. Add waste (10% is typical) and divide by 100 for squares.
Common questions
How do I calculate how much siding I need?
Perimeter × wall height gives the rectangular walls; add a triangle for each gable end; subtract about 15% for windows and doors; then add 10% waste. A 40 × 30 ft two-storey house with no gables needs about 2,140 sq ft of siding, or 23.6 squares to order.
What is a square of siding?
100 square feet of wall coverage. Siding is priced and ordered by the square.
How much does new siding cost?
Installed, roughly $6–$12 per sq ft for vinyl, $9–$16 for engineered wood, $10–$20 for fiber cement and $12–$25 for natural wood. Tear-off, house wrap and trim add to it.
How accurate is this?
Close enough to budget — usually within about 10% on a simple house. Dormers, bay windows, a walk-out basement and a porch inside the footprint change the wall area, so confirm with a contractor before ordering.
Skip the tape measure.
Type your address, confirm the storeys, and compare vinyl, engineered wood and fiber cement for your actual house — measured from satellite.
- Free, no credit card
- Works on any US address
- Three options, good to best
- No site visit to get a number