Floors & Walls
Countertop Square Footage Calculator
Add up countertop sections, subtract cutouts, and see gross and net square footage.
Enter your measurements
Results update as you type.
About this calculator
Enter each rectangular section of countertop, plus any cutouts (sink, cooktop). The result shows gross and net area separately, because fabricators may bill either way — pick the billing basis your quote uses.
How to use this calculator
- Sketch the countertop and split it into non-overlapping rectangles.
- Enter each section's length and depth.
- Enter the total area of sink and cooktop cutouts.
- Choose whether your fabricator bills gross or net area.
Formula
Gross area = sum of section length × width
Net area = gross − cutouts
Price basis = gross or net, as selected
Assumptions
- Sections must not overlap — an L-shape is two rectangles, not the outer rectangle counted twice.
- Cutouts larger than the gross area are rejected.
- Both gross and net are always displayed so billing differences are visible.
Common mistakes
- Counting the overlapping corner of an L-shaped top twice.
- Subtracting cutouts when the fabricator bills gross area.
- Converting net face area straight into a slab order without a cutting layout.
Worked example
Try it: press “Load example” above the form.
96 × 25.5 in plus 36 × 25.5 in is 23.375 ft² gross; minus a 432 in² cutout, 20.375 ft² net.
Limitations
No slab nesting or fabrication quote. Fabricators may bill cutout material — check your quote's basis.
Frequently asked questions
Should I include sink cutouts?
The geometry can subtract excluded areas where requested, but a fabricator may price the full slab or charge separately for cutouts. Confirm the quote’s measurement basis.
Does square footage tell me the slabs to buy?
No. Slab size, seams, grain, vein matching, edges and cutting orientation require a fabrication layout. The tool estimates net face area only.
What does the worked example show?
96 × 25.5 in plus 36 × 25.5 in is 23.375 ft² gross; minus a 432 in² cutout, 20.375 ft² net.
Which assumptions should I check before using the result?
No slab nesting or fabrication quote. Fabricators may bill cutout material — check your quote's basis.
Sources
Sources explain the methods and any named product presets. Check your product label where coverage, yield or density differs.
Calculation documentation · Updated 2026-11-08 · Version 1.6.4. Estimates are planning aids. Confirm quantities, coverage and prices with your supplier before purchasing. Found an error? Report it.
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