Enter your wall perimeter, height, gables, and openings once and get siding squares to buy alongside a concrete estimate for any slab or footing work on the same exterior job.
Siding takeoffs live or die on net wall area — gross wall area plus gable triangles, minus every door and window opening, before waste is applied. This page runs that net-area math and, separately, a slab or footing concrete estimate for exterior work that often rides along with a siding job (an entry stoop, a small pad). Each calculator below is the same one available on its own page — nothing here is a new formula.
Wall perimeter times wall height gives gross wall area. Gable triangles (half base times height, one per gable end) add to that. Every door and window opening then subtracts from the total, since siding doesn’t get installed over an opening. What’s left is net area, which this calculator converts into “squares” — the trade unit most siding products are sold and estimated in, where one square covers 100 sq ft.
Measure perimeter along the actual wall line at the base of the structure, and measure each opening’s width and height directly rather than assuming a standard size — window and door rough openings vary enough between jobs that an assumed size introduces real error into the takeoff.
Pick the siding product, then enter wall perimeter, height, corner count, gables, and each opening's width and height once for the Siding takeoff below. Slab/footing fields are separate since a concrete pour tied to exterior work isn't sized from wall dimensions.
Net wall area and siding squares to buy from wall perimeter, height, gables, and openings.
You'll need — panels of siding for — sq ft of wall.
You'll need
Sized on the gross wall: the wrap is run over the openings and cut out afterwards.
Slab or footing concrete volume and optional bag count for exterior work tied to this job.
Order — cu yd of concrete for this pour.
Order
Volume yield per bag, as printed on the bag. NOT cured weight / dry bag weight -- that double-counts the mix water and over-orders by 12.5%.
Siding waste covers more than offcuts: lap siding loses material to overlap and to matching courses around corners and openings, panel products lose material to alignment on irregular wall lengths, and any job with more corners or a more complex roofline needs a higher waste percent than a simple rectangular wall. CrewMeasure starts at 10%, but that number is always shown and editable rather than baked silently into the squares total.
Accessory linear footage (trim, J-channel, starter strip) tracks wall perimeter directly and is reported alongside the squares total. Corner trim and opening trim are counted from the corner count and the opening sizes you enter — neither is guessed from perimeter, because a rectangle and an L-shaped footprint measure the same and a 12 sq ft window is 3 x 4 or 2 x 6. Leave either field blank and that line is reported as not counted rather than estimated.
Net area only removes the flat opening area from the wall — it does not add back the extra material J-channel and trim details around each opening actually consume, which is one reason the waste percent exists as a visible, editable input rather than a fixed constant. Corner posts and window/door trim run off the corner count and opening sizes entered above; soffit and fascia are a separate material line this calculator does not estimate.
A slab or footing poured as part of the same exterior job (an entry landing, a small equipment pad) uses its own dimensions, entered separately below, and runs through the same Concrete calculator available on its own page.
No. Slab length, width, and depth are entered separately from the wall perimeter and height, since a concrete pour tied to exterior work (an entry pad or footing) isn't sized from the wall dimensions above it.
Yes. Flip either section to "Manual entry" to edit its inputs directly without changing the other calculator.
This page starts with the gables you enter in the master input list; each gable's base and height are entered separately since a building can have gable ends of different sizes.
Yes. It sets the starting waste percent (vinyl and metal panel 10%, fiber cement and the board systems 12%), names the corner and opening trim the way that system names it (a channel the siding tucks into, or a flat casing it butts against), and tags the material list line with that product rather than a generic one. The waste percent stays editable after the switch.
Corner trim and opening trim, yes — but only from numbers you enter. Corner trim needs the corner count and opening trim needs each opening's width and height, because a perimeter cannot say how many corners a footprint turns and an area has no edge to run casing along. Leave either blank and the line is reported as not counted rather than guessed. Soffit, fascia and the rest of the trim package still need a manual count.
Material estimate and general reference only. Verify manufacturer coverage rates, local code, and field conditions before ordering or starting work.