1200 ft2 exterior wall area
- Net wall area
- 1080 ft2
- Area with waste
- 1188 ft2
- Estimated cost
- $2,160.00
Gables, trim, starter strips, J-channel, corners, product exposure, and installer layout need separate planning.
Siding Calculator
Use this free siding calculator to estimate exterior siding squares from wall square footage, door and window openings, waste, and optional price per square.
Research-backed assumptions Formula steps Examples included Private in-browser use
Formula steps
- Subtract doors and windows from the measured exterior wall area.
- Add a waste factor for cuts, corners, and trim-heavy sections.
- Divide by 100 square feet per siding square and round up.
How to use the siding calculator
- Enter exterior wall square footage, opening area, waste percent, and optional price per siding square.
- Press Estimate siding to see net wall area, adjusted area, and 100-square-foot siding squares.
- Use measured gables and wall sections when possible instead of a rough rectangle.
- Trim, starter strips, J-channel, corners, exposure, and installer layout need separate planning.
Common uses
Estimate vinyl, fiber cement, wood, or engineered siding squares.
Convert wall square footage into 100-square-foot siding squares.
Subtract doors and windows before adding waste.
Add optional price per square for an early material estimate.
Examples
12 squares
Siding squares estimate
Estimated material cost
Frequently asked questions
Plain-language answers about when to use the tool, what it does with your inputs, what to double-check, and how privacy works.
When should I use the Siding Calculator?
Use it when your task matches one of these common needs: Estimate vinyl, fiber cement, wood, or engineered siding squares. Convert wall square footage into 100-square-foot siding squares. It works best when you already know the values, dates, units, or settings the page asks for.
What is the Siding Calculator doing with my inputs?
In plain language: The calculator subtracts openings from wall area, adds waste, divides by 100 square feet per siding square, and rounds up. The examples on the page are there so you can compare your inputs with a filled-out calculation before copying the answer.
What do the main Siding Calculator inputs mean?
Wall area: total exterior wall square footage before doors and windows are subtracted. Doors/windows: the combined opening area removed before the siding waste allowance is added. Siding square: a siding unit equal to 100 square feet of coverage. Waste percent: extra siding for cuts, gables, corners, trim-heavy sections, and damaged pieces.
How should I read the Siding Calculator answer?
Read the headline estimate first, then check the material, waste, coverage, and unit lines. For project tools, the supporting lines are often the difference between a rough idea and a list you can actually shop from.
What should I double-check before trusting the answer?
Siding projects also need gables, corners, starter strips, trim, channels, product exposure, color lots, installer layout, and local building review. Also check that you used the right unit, date, scale, or mode because small input changes can change the result.
Does the site save what I enter?
No. The calculator runs in your browser tab. Your recent answers stay only on the page while you use it, and they are not sent to a server.
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