Countertop Cost and Square Footage Calculator

Enter your layout, cutouts, backsplash and edge profile once. See the math for your square footage, an estimated slab count per material, and installed cost ranges for every common countertop material side by side, each figure sourced and dated. No sign-up and no email needed to use it.

How this is calculated

1. Area. Each straight run is length x depth / 144 square feet. Measured wall to wall, one depth x depth corner square is subtracted for every inside corner (one for an L, two for a U), and 1.5 in of length is added per exposed end. An island, peninsula or extra section is added as its own length x depth / 144. Sink and cooktop cutouts are never subtracted.
2. Material cost. Area x the installed price per square foot from the national cost guides, at the low, typical and high figures for each material. Those prices already include fabrication and installation, so no waste charge is added.
3. Add-ons. Each add-on is priced from its own published range, with the typical figure at the midpoint: a 4 in backsplash by linear foot, edge profile by linear foot, waterfall panels per side, sink, cooktop, faucet-hole and outlet cutouts as flat amounts, and tear-out by square foot. A full-height backsplash is priced by square foot instead, from $10 a square foot at the low end up to the material's own installed price for the typical and high cases. Two optional flat lines are off unless you tick them: plumbing reconnect ($150 to $400) and overhang support brackets ($200 to $700).
4. Total. All the unrounded lines are summed for the low, typical and high cases, then rounded once to the nearest $50.
5. Slabs. Two estimates are shown as a range: a lane-packing fit of your pieces onto published slab sizes, and total slab area x 1.10 (straight runs and galleys) or x 1.15 to 1.25 (L, U or island layouts), divided by the slab area and rounded up. The low end is never below a layout that actually fits.

Left out on purpose: local labor rates, delivery, plumbing and electrical work beyond the cutouts and the optional plumbing reconnect line, and where a fabricator will place seams. The next section works one kitchen through every step, and the section after it explains where each price range comes from.

Worked example: the kitchen the calculator opens with

How we got these ranges

Every installed price range on this page comes from national cost guides (HomeGuide, Fixr, HomeAdvisor, Bob Vila, Homewyse, Angi and Forbes), checked September 29, 2026. Some add-on figures come from individual fabricators, retailers or smaller guides instead, because no national guide prices them cleanly: waterfall panels (Alpine Stones, a Portland, Oregon fabricator, $900 to $2,500 per leg; Granite Guy in Massachusetts, $1,500 to $2,500 per side), farmhouse sink cutouts (Alpine Stones, $300 to $600), overhang supports (Alpine Stones, $200 to $700), the low ends of the drop-in ($75) and undermount ($150) sink cutouts (Alpine Stones), plumbing reconnect (Alpine Stones, $150 to $400; Cost to Renovate, $150 to $300), the $30 high end of the 4 in backsplash (Dynamic Stone Tools, a stone-tool supplier, $15 to $30 per linear foot) and the $80 high end per extra faucet hole (Marble.com, for holes over 1 3/8 in). Where sources disagree, we kept the disagreement instead of picking one. The "typical" figure is a published average where one exists (for example Fixr's average project cost divided by its stated square footage). Otherwise it is a point inside the published range, usually the midpoint, that we chose; our data file says which, material by material.

Homewyse consistently runs higher than every other guide because it prices a fixed 129 square foot "default" job rather than a range of real jobs, so we did not treat it as typical, only as part of the high end. HomeGuide's page dates say "2026" in the title but its underlyingdateModified field is often from 2023 or 2024; we show HomeGuide's figures anyway because the dollar ranges match what Fixr and HomeAdvisor publish today, and we checked the live page on the date shown. This Old House's stone cost ranges (for example "$10 to $140 per square foot installed" for granite) read like material-only pricing tables rather than true installed cost, so we left them out rather than blend in a number that does not match its own label.

This calculator gives national ranges, not a local quote. We found no sourced regional cost multiplier worth publishing, so no city adjustment is applied anywhere on this page.

How slabs are sold

Engineered quartz and natural stone are sold as full slabs, not by the square foot cut to order. A standard quartz slab runs roughly 120 by 55 in (Fixr). Jumbo quartz slabs run about 128 to 132 in long and 64.5 to 65.5 in wide (Caesarstone, Cambria), and Caesarstone says its jumbo slabs yield about 20% more surface area than standard. Granite slabs vary more by block, commonly 108 to 132 in long and 60 to 78 in wide (Nova Tile & Stone). For each material the calculator uses one smaller and one larger size from these published slab sizes (manufacturers and fabricators); where a size is our pick inside a published range rather than a size a source names, our data file says so.

Whatever area your layout does not use on a slab is waste. That is why the calculator shows a slab count, not just a square footage: two kitchens with the same area can need a different number of slabs depending on how the pieces fit. A same-material backsplash and waterfall panels come out of the same slabs, so they count toward the slab total even though they are priced separately.

Laminate, solid surface and butcher block are sold as sheets or set-length pieces rather than natural-stone-style slabs, and concrete is cast to order, so this calculator does not estimate a slab count for those materials; it shows "made to order" instead.

When a seam happens

Expect a joint at each inside corner of an L or U kitchen, where two runs meet as separate pieces; EdStone says every L-shape or U-shape kitchen has at least one seam. A seam is also forced whenever a single continuous piece is longer than the slab you are using. National guides fold seam labor into the installed price rather than charging for it separately (Fixr says seams are filled with color-matched epoxy as part of the job), so this calculator never adds a per-seam dollar charge to the total. It does flag when a piece is longer than the slab and so likely forces a seam (its seam count covers only those pieces, not the corner joints), and it flags when an island or other piece is deeper than a slab is wide, naming the larger slab size that fits or saying a seam is needed when none does. Exactly where a seam lands on the finished counter is a decision your fabricator makes from the real slab, not something a calculator can know in advance.

What this calculator will not tell you

• This is not a quote and not a local price. It shows national ranges; ask any local fabricator for their own written price.
• It will not say exactly how many slabs you need or exactly where a seam will fall. Only the fabricator's layout on the actual slab decides that.
• It will not tell you a single "best" or "cheapest" material. Every material is shown with the same published ranges, in the same order of transparency.
• It does not add a waste charge on top of the installed prices shown. Every installed figure already includes the fabrication and installation the source describes.