Siding Calculator
Enter your wall area and the openings to deduct to estimate siding squares and an optional cost.
Results
- Siding squares
- 12.1 squares
- Net wall area
- 1,100 sq ft
- Area incl. waste
- 1,210 sq ft
Estimates only. Round up and buy a little extra to account for waste, spills, and breakage.
Enter your wall area and the openings to deduct to estimate siding squares and an optional cost.
How to use the siding calculator
- Enter the wall perimeter in ft.
- Enter the wall height in ft.
- Enter the doors & windows.
- Enter the waste factor in %.
- Optionally add a price to estimate the total project cost.
- Read your quantities instantly — no sign-up, and you can print the estimate to take to the supplier.
Worked example
Inputs
- Wall perimeter
- 140 ft
- Wall height
- 9 ft
- Doors & windows
- 8
- Waste factor
- 10 %
Results
- Siding squares
- 12.1 squares
- Net wall area
- 1,100 sq ft
- Area incl. waste
- 1,210 sq ft
Using the example values above, the siding calculator returns 12.1 squares (siding squares). Change any field to match your own project and the numbers update instantly.
How much extra should I order?
Always order a little extra. A 5% waste factor suits simple, square projects; 10% is right for most jobs; bump it to 15–20% for irregular shapes, diagonal patterns, or uneven ground. Running short almost always costs more than the leftover material.
Formula
Net area = wall area − openings. Squares = net area ÷ 100, × (1 + waste%).
Frequently asked questions
- How much siding waste should I plan for?
- Add 10% for simple walls and up to 15% for homes with many corners and gables.
- What is a square of siding?
- A square covers 100 square feet of wall, the same unit used for roofing.
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