Use this free siding calculator to turn measured wall and gable area into exact siding squares, rounded whole squares, boxes, and material cost.
1200 ft2 walls + 0 ft2 gables
Opening-deduction methods vary. Check the product worksheet, box coverage, trim, starter strip, J-channel, corners, exposure, and installer layout before ordering.
Recent siding estimates will appear here.
Siding estimates stay local and use wall area, gables, openings, waste, box coverage, and optional price per 100-square-foot square.
Inputs and recent answers stay in this browser tab and are not sent to a server.
Estimate vinyl, fiber cement, wood, or engineered siding squares.
Convert wall square footage into 100-square-foot siding squares.
Add triangular gables without hiding their area inside a waste guess.
Compare a chosen opening deduction with the product worksheet.
Add optional price per square for an early material estimate.
Convert exact squares into whole boxes using the package label.
Keep siding coverage separate from trim, channel, soffit, fascia, wrap, and labor.
11.88 exact squares, round to 12
100 ft2, or 1 siding square before waste
2.97 exact squares, round to 3
6 whole boxes
$2,160 material estimate
Need a slower walkthrough, a related calculator, or the full library? These links keep you close to the task you started.
Plain-language answers about when to use the tool, what it does with your inputs, what to double-check, and how privacy works.
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 measurements, amounts, units, or options the page asks for.
In plain language: Gross area = rectangular wall area + triangular gable area. Net area = gross area - chosen opening deductions. Area with waste = net area x (1 + waste percent / 100). Exact siding squares = area with waste / 100. Whole squares = ceiling(exact squares). Boxes = ceiling(exact squares / squares per box). Material cost = whole squares x price per square. The examples on the page are there so you can compare your inputs with a worked example before copying the answer.
Wall area: combined rectangular exterior wall square footage before gables and opening deductions. Gable area: combined triangular area found with width times peak height divided by 2 for each simple gable. Doors/windows: the opening area you choose to remove before waste; check the product worksheet because methods differ. Siding square: a siding unit equal to 100 square feet of coverage. Squares per box: the package coverage printed on the siding box or bundle label. Waste percent: extra siding for cuts, gables, corners, trim-heavy sections, and damaged pieces.
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.
Opening deductions vary by product worksheet. Siding projects also need corners, starter strips, J-channel, trim, box coverage, panel exposure, color lots, installer layout, weatherproofing, and local building review. Also check the unit, scale, mode, and result limit because small input changes can change the answer.
It estimates net wall area, area after waste, siding squares, rounded whole squares, optional box count, and optional material cost.
One siding square means 100 square feet of installed coverage. The calculator divides adjusted square feet by 100 to estimate squares.
Yes. Use it for a vinyl siding material estimate when you know the wall area, opening area, waste percent, and product coverage.
Yes for rough square-foot and square estimates. Check the product label because board exposure, profile, and box coverage can change the real order.
Estimate each simple triangular gable as width times peak height divided by 2, add the gable areas together, and enter that number in Gable area.
Follow the product or supplier worksheet. Some guides subtract measured openings and then add waste. Vinyl guidance may leave ordinary windows and doors in the area as a waste allowance and deduct only very large openings.
It divides the exact siding squares by the coverage printed on one box or bundle, then rounds up. A result of 11.88 squares with 2 squares per box becomes 6 boxes.
No. It estimates siding coverage. J-channel, starter strip, corner posts, trim, soffit, fascia, fasteners, house wrap, and labor need separate checks.
A simple wall may use around 10% waste, while complex gables, corners, repairs, and many cuts may need more. Ask the supplier or installer if the layout is tricky.
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.