Countertop Calculator
This countertop calculator finds the square footage of your kitchen or bathroom countertops from the length and depth of up to three sections, plus an optional backsplash. Add a waste allowance and a price per square foot, and the countertop calculator returns the total area and an estimated material cost for granite, quartz, laminate, or any other surface.
Results
The Countertop Calculator is part of our Rooms & Spaces collection. Browse more rooms & spaces to size, convert, and check your work alongside this tool.
What the countertop calculator does
Fabricators price stone and solid surface tops by the square foot, so the first number you need is the area. The countertop calculator multiplies each section length by its depth, adds the backsplash strip along the back edge, and applies a waste allowance for seams, cutouts, and slab layout. If you enter a price per square foot it multiplies through for a material estimate you can compare with quotes.
Countertop square footage formula
Each section is a rectangle; divide square inches by 144 for square feet:
Cost equals the total area times the price per square foot. The calculator also shows the total in square meters.
Countertop calculator example
An L shaped kitchen with a 96 in run and a 60 in run, both 25.5 in deep, a 4 in backsplash, and 10% waste:
At $60 per square foot that comes to about $2,109.25. A separate 72 × 36 in island adds 18 sq ft, or 19.8 sq ft with waste.
How to use the countertop calculator
Break the countertop into rectangles. Measure each run along the wall in inches and its depth from the wall to the front edge, usually 25.5 in for kitchen base cabinets with a 1.5 in overhang. For an L shape, measure the first run to the corner and the second run from the front edge of the first, so the corner square is counted once. Enter an island as its own section. Add the backsplash height if the same material runs up the wall.
Reading the countertop square footage
The counter surface is what you walk up to; the backsplash is the strip on the wall; the total includes waste. Stone fabricators often charge for the whole slab you use, so a small job can cost more per square foot than a large one. Do not subtract the sink or cooktop cutout: the stone is still bought and cut, and cutouts often carry their own fee. Use the total as your starting point and let the fabricator template the final size.
When to use a countertop cost calculator
- Budgeting a kitchen remodel
- Comparing granite, quartz, and laminate prices
- Checking a fabricator quote
- Planning an island or bar top
- Pricing bathroom vanity tops
Common countertop calculator mistakes
- Counting the corner twice. Measure the second leg of an L from the first leg front edge.
- Using cabinet depth. Add the front overhang, usually to 25.5 in.
- Subtracting the sink. The stone is still bought and cut.
- Forgetting the island overhang. Seating overhangs add a lot of area.
Tips for a countertop estimate
- Get at least two quotes on the same square footage.
- Ask to see the slab and approve the seam locations.
- Keep remnant pieces for a vanity or shelf.
How to measure countertops for an accurate estimate
Measure along the wall at the back of the cabinets, since walls are rarely square and the front edge can run longer. Add the overhang at any open end, usually 1 to 1.5 in, and at a seating overhang on an island, often 10 to 12 in so stools fit. For a U shaped kitchen, take the middle run at full length and measure both side runs from its front edge. Peninsulas and islands go in as separate rectangles. Round each measurement up to the next inch; the fabricator will template the exact shape after the cabinets are in, and your number only needs to be close enough to budget. If the job also includes a tiled backsplash above a short stone lip, size the tile with the tile calculator and enter only the stone lip height here.
Granite and quartz countertop calculator tips
Stone is cut from slabs, typically around 9 to 10 ft long for granite and slightly larger for quartz, so the number of slabs often drives the price more than the exact area. A run longer than one slab needs a seam, and a large island may need a full slab of its own. Ask whether a quote is per square foot installed or per slab, and whether edge profiles, sink cutouts, and removal of the old top are included. Laminate and butcher block are bought in stock lengths, so for those materials round each run up to the next stock size instead of adding a percentage waste.
Countertop square footage chart
Square feet for standard 25.5 in deep kitchen runs, with and without a 10% waste allowance:
| Run length | Square feet | With 10% waste |
|---|---|---|
| 48 in (4 ft) | 8.50 | 9.35 |
| 72 in (6 ft) | 12.75 | 14.03 |
| 96 in (8 ft) | 17.00 | 18.70 |
| 120 in (10 ft) | 21.25 | 23.38 |
| 144 in (12 ft) | 25.50 | 28.05 |
Countertop Calculator FAQ
How do you calculate countertop square footage?
Multiply the length by the depth of each rectangle in inches, add them up, and divide by 144. A 96 × 25.5 in run is 17 sq ft.
How do I measure an L shaped countertop?
Measure one leg to the corner at full length, then measure the other leg from the front edge of the first, so the corner square is counted only once.
What is the standard countertop depth?
Kitchen counters are usually 25 to 25.5 in deep over 24 in base cabinets. Bathroom vanity tops are often 19 to 22 in deep.
Should I include the backsplash?
Include it if the backsplash is made of the same slab material. A tiled backsplash is priced separately with the tile calculator.