Countertop Square Footage Calculator

Countertop square footage is just length times depth for each run, added up. The catch is the details: standard tops run about 25 to 26 inches deep once you count the overhang, corners get double counted if you're not careful, and the slab you actually buy comes with waste baked in. Enter your runs below and the tool does the arithmetic. The rest of this page shows you how to measure so the number is right.

How to calculate countertop square footage

Every countertop is a set of rectangles. Measure each one, multiply length by depth, and add them together. The only conversion you need is inches to square feet: multiply length and depth in inches, then divide by 144, since there are 144 square inches in a square foot.

Square feet = (length in inches × depth in inches) ÷ 144

Standard base cabinets are 24 inches deep, and the finished countertop sits a little past the cabinet face. With a typical 1 inch to 1.5 inch overhang, most tops measure about 25 to 26 inches deep. Arch City Granite, a stone fabricator, pegs the standard at "about 25 inches" and notes granite usually gets a 1.5 inch overhang versus a half inch for laminate. Measure your own overhang rather than assuming, because a bar or an exposed end can push it out further.

Do the depth for every run the same way, then treat the length of each run as the distance along the wall.

Converting linear feet of cabinets to countertop square footage

If all you have is the linear footage of your cabinet run, you can still get close. A linear foot of run at a 25 inch depth covers 25 ÷ 12 = 2.08 square feet. At 26 inches it's 2.17. So multiplying your linear feet by roughly 2.1 gets you in the ballpark for a standard depth top.

Rough estimate: countertop sq ft ≈ linear feet of run × 2.1

Twelve linear feet of cabinets works out to about 25 square feet. That's an estimate for budgeting, not a cutting list. Once you're ordering slab, measure every run in inches and use the exact depth, because a bar overhang or a deeper island changes the multiplier.

Watch the corners

Here's the mistake that trips people up on L-shaped and U-shaped kitchens. Where two runs meet at a corner, the square patch in that corner belongs to both rectangles. If you measure each leg full length and add them, you count that corner twice.

Fix it by subtracting one corner square per inside corner. A 25.5 inch deep top has a corner square of 25.5 × 25.5 = 650 square inches, or about 4.5 square feet. Subtract that once for each place two runs meet.

Worked example: an L-shaped kitchen

Say you've got an L with a back run along one wall and a return down the side, plus a freestanding island.

Back run: 120 inches long × 25.5 inches deep = 3,060 sq in.
Return run: 72 inches long × 25.5 inches deep = 1,836 sq in.
Corner overlap (subtract once): 25.5 × 25.5 = 650 sq in.

Countertop area for the L = 3,060 + 1,836 − 650 = 4,246 sq in. Divide by 144 and you get 29.5 square feet.

Now the island. A 6 foot by 3 foot island is 72 × 36 = 2,592 sq in, which is 18 square feet. Add it to the L and the job totals about 47.5 square feet of finished top. That lines up with the range fabricators quote; Arch City puts the average kitchen at roughly 30 square feet for the perimeter alone, and a decent island pushes a real kitchen well past that.

Backsplash area

Backsplash is usually measured and priced on its own, because it's vertical and often a different material. Measure it as length times height like any other rectangle.

A short splash of 4 inches is common with laminate and some stone: 120 inches of run × 4 inches = 480 sq in, or 3.3 square feet.
A full-height splash to the underside of the wall cabinets is often about 18 inches: 120 × 18 = 2,160 sq in, or 15 square feet.

Full-height stone backsplash eats slab fast, so price it separately before you commit.

How fabricators price it, and why waste matters

Stone shops quote per square foot of finished countertop, but they buy in slabs, and a slab is a fixed rectangle. Common slab sizes run about 55 to 70 square feet each. Your 47.5 square foot kitchen won't nest perfectly into one slab. Sink cutouts, seams, edge profiles, and the fact that veined stone has to be laid out for pattern all create offcuts you pay for.

Plan for 10 to 20 percent waste on straightforward quartz and granite layouts, and more when you want book-matched veining or you're working around a big island that forces a seam. If your finished top is 47.5 square feet, a fabricator may charge you for 55 or more square feet of material once yield and waste are figured in. That's why two shops can quote the same kitchen differently: they're making different assumptions about how your job nests into their slabs.

It pays to measure carefully before you get quotes. In a long forum thread on Anandtech titled "Contractor miscalculated countertop space and cut the slabs," a homeowner learned the hard way what happens when the layout math is wrong before the saw runs. Fabricators will template your kitchen with a laser before cutting, but a good square footage estimate up front keeps your budget honest.

Common mistakes

Using 24 inches for depth. That's the cabinet depth, not the countertop depth. The overhang adds 1 to 2 inches. Measure the finished top, not the box.

Double counting corners. The single most common error on L and U shapes. Subtract one corner square per inside corner.

Forgetting the island and the overhangs. A seating overhang on an island can be 10 to 12 inches deep on the seating side, which adds real area. Measure it, don't eyeball it.

Confusing finished square feet with slab square feet. The number you calculate is the top you'll use. The number you pay for includes waste. Ask any fabricator how they figure yield.

For tiled counters or a tile backsplash, our tile calculator handles the coverage and waste factor. If you're measuring the whole kitchen, the room calculator and the how to calculate square footage guide walk through odd shapes step by step.

Frequently asked questions

How do you calculate countertop square footage?

Measure each run's length and depth in inches, multiply them, and divide by 144 to get square feet. Add the runs together, then subtract one corner square for every inside corner where two runs meet so you don't double count. Standard depth is about 25 to 26 inches once you include the overhang.

How do you calculate square footage of a countertop from linear feet?

Multiply the linear feet of cabinet run by about 2.1 for a standard 25 to 26 inch deep top. Twelve linear feet comes out to roughly 25 square feet. This is a budgeting estimate; for an order, measure each run in inches with its actual depth.

How much countertop do I need for a typical kitchen?

A perimeter of countertops in an average kitchen runs around 30 square feet, and adding an island commonly pushes a real kitchen to 45 to 55 square feet of finished top. Your number depends on the layout, the island size, and any bar overhangs.

Why does the fabricator charge me for more square feet than I measured?

Fabricators buy stone in fixed slabs of about 55 to 70 square feet and cut your pieces from them. Sink cutouts, seams, edge work, and pattern matching create offcuts you pay for, so most jobs carry 10 to 20 percent waste. Your finished top of 47 square feet might be billed at 55 or more.

Should I include the backsplash in my countertop square footage?

Measure it, but keep it separate. Backsplash is usually priced on its own because it's often a different material and always a different piece. A 4 inch splash adds a few square feet; a full-height stone splash can add 15 or more per wall.

For any other shape or a whole project at once, start from the main square footage calculator.

Countertop Square Footage Calculator