Countertop Square Footage Calculator
Order the right amount the first time: this countertop square footage calculator measures straight, L-shaped, or galley layouts, then prices the stone from about $20 per sq ft (laminate) to $200+ per sq ft (marble) — cutting-waste allowance included.
The corner square is counted once — the overlap is subtracted automatically.
Standard countertop depth is 25.5 inches (2.125 ft) including the front overhang. Measure each run wall-to-wall along the back.
Estimates only. Material rates are installed ballparks and vary by region, edge profile, and slab grade. Confirm final measurements with your fabricator before ordering.
How the countertop square footage calculator works
Countertops are sold by the square foot, so every layout reduces to length times depth. A straight 10 ft run at the standard 25.5-inch depth is 10 × 2.125 = 21.25 sq ft — measure wall-to-wall along the back of each run.
L-shapes need one correction: the corner square gets counted twice if you just add both runs, so the calculator subtracts one depth-by-depth square. Galley kitchens are simply two straight runs added together.
Then comes waste. Fabricators order 10% extra as standard — 15% for strongly veined stone where pattern matching eats usable slab. Multiply the order quantity by the installed material rate ($20–$50 laminate up to $80–$200 marble) for the budget number.
sq ft = L × D (minus one corner square for L-shapes) · order = sq ft × (1 + waste) · cost = order × material rate
Related tools
Keep exploring: Kitchen Remodel Cost Calculator · Cabinet Refacing Cost Calculator · Bathroom Remodel Cost Calculator — roll the counter number into the full kitchen budget.
Countertop square footage calculator FAQ
How do you calculate countertop square footage?
Multiply each run’s length by its depth in feet: a 10 ft run at 25.5 inches deep is 10 × 2.125 = 21.25 sq ft. For L-shapes, add both runs and subtract one depth-by-depth corner square. Measuring in inches? Divide the total square inches by 144.
How much countertop do I need for a 10x10 kitchen?
About 25–30 sq ft for a typical 10×10 kitchen with an L-shaped layout — roughly 8 ft + 10 ft runs at standard depth, plus the 10% cutting-waste allowance fabricators add.
What is the standard countertop depth?
25.5 inches (2.125 ft), including the roughly 1-inch overhang past the 24-inch-deep base cabinets. Islands and peninsulas vary — measure the actual overhang on both sides.
How much waste should I add for countertops?
Ten percent is the industry standard for straight runs and simple L-shapes. Bump to 15% for strongly veined granite or marble, where the fabricator must match the pattern across seams.
How much does quartz cost per square foot installed?
About $60–$150 per square foot installed, covering the slab, templating, cutting, and installation. Premium colors and thick mitered edges push past $150.
Is granite or quartz cheaper?
Granite is usually slightly cheaper ($50–$120 installed vs $60–$150 for quartz), but quartz pricing is more predictable — granite varies with slab rarity and origin. Both outlast laminate by decades.
How many slabs do I need for my countertops?
A standard stone slab yields about 30–35 sq ft of usable countertop. Divide your order quantity (net sq ft plus waste) by 32: a 40 sq ft order needs 2 slabs.