Countertop Square Footage Calculator
Calculate countertop area for kitchen or bathroom
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Need to calculate countertop area for kitchen or bathroom? Countertop Square Footage Calculator answers in seconds. Type Section 1 Length (inches), Section 1 Depth (inches) and Section 2 Length (inches) into Countertop Square Footage; each keystroke re-runs the math. Every Countertop Square Footage answer can be reproduced by hand. Anyone comparing options in Home & Garden can use Countertop Square Footage to compare scenarios. Countertop Square Footage runs in your browser. Home & Garden data stays in the tab. Countertop Square Footage handles kitchen counter sqft the same way as free online countertop square footage calculator — one of the Home & Garden tools on CalcProMaster. Countertop Square Footage answers the next Home & Garden question you meet.
What the defaults give
One 120 × 25.5 inch section is 21.3 sq ft net, and with 10% waste you order 24 sq ft.
The 4-inch backsplash adds 3.3 sq ft, and the exposed front edge is 10 linear feet.
The formula
Section area (sq ft) = length × depth ÷ 144
Total = section 1 + section 2
Order = ceil(total × 1.10)
Backsplash = (total length ÷ 12) × (height ÷ 12)
The 144 converts square inches to square feet. Waste is applied before rounding up, so a small job still gets a whole square foot of slack rather than being ordered exactly to the measured area.
Worked examples
120 × 25.5 in → 21.3 net → 24 sq ft ordered
96 × 25.5 in → 17.0 net → 19 sq ft
60 × 25.5 plus 84 × 25.5 → 25.5 net → 29 sq ft
96 × 36 in island → 24.0 net → 27 sq ft
120 × 25.5 in with no second section → 24 sq ft
Same run, 6 in backsplash → 5.0 sq ft of splash instead of 3.3
Measure the way a fabricator measures
Depth is measured from the wall to the front edge, including any overhang, and runs are measured wall to wall rather than between cabinet boxes. A standard base cabinet is 24 inches deep with a 1 to 1.5 inch overhang, which is where the 25.5 default comes from. Measure at three points along each run — walls are rarely square, and the largest figure wins because the slab cannot be squeezed.
L-shaped kitchens are usually ordered as one piece if the total length fits the slab. A typical quartz slab is 56 to 63 sq ft, so 29 sq ft of L-shape comes out of one slab with a seam avoided; two separate runs totalling more than the slab need a seam, and seams cost both money and appearance.
What the area does not include
Cutouts for a sink or hob do not reduce the slab you buy — you pay for the full rectangle and the offcut is waste unless the fabricator can reuse it. Edge profiles are priced per linear foot, which is why the edge figure matters as much as the area: a 2-inch mitred edge on 10 feet can add more to the quote than another square foot of stone.
Backsplash is often priced separately, and a full-height splash behind a hob is measured as its own rectangle rather than the 4-inch strip. Add the sink, tap holes, and any waterfall end panels to the order before comparing quotes, since fabricators quote to different inclusions.
Frequently Asked Questions
How many square feet is a 120 by 25.5 inch counter?
21.3 sq ft net. With 10% waste the order is 24 sq ft, which is the figure a fabricator will price.
Why add 10% waste?
For cuts around a sink or hob, mitres and measurement error. The calculator applies it before rounding up, so the order is always a whole square foot.
How much backsplash does a 120 inch run need?
3.3 sq ft at a 4 inch height, because 10 linear feet times 0.333 feet is 3.3. A 6 inch splash would be 5.0 sq ft.
Do sink cutouts reduce the slab I buy?
No. You pay for the full rectangle and the cut-out piece is waste unless the fabricator can reuse it elsewhere.
How should I measure depth?
From the wall to the front edge including overhang, at several points along the run, and use the largest measurement since walls are rarely square.
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