Countertop Square Footage Calculator
Last updated
Kitchen layout
Standard: 25–25½ in (64–65 cm).
0 for none, 4 in standard.
0 if no island.
Total countertop area
57.73 sq ft
- Counter runs and island
- 51.73 sq ft
- Backsplash
- 6 sq ft
- Slabs to order
- 2 (45.83 sq ft each)
- Island seats (24 in each)
- 3
Fabricators quote from their own template; use this for budgeting and comparing quotes.
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Countertop square footage by run length (25½ in deep)
| Run length | Square feet | Square metres |
|---|---|---|
| 48 in (4 ft) | 8.5 | 0.79 |
| 72 in (6 ft) | 12.75 | 1.18 |
| 96 in (8 ft) | 17 | 1.58 |
| 120 in (10 ft) | 21.25 | 1.97 |
| 144 in (12 ft) | 25.5 | 2.37 |
| 180 in (15 ft) | 31.88 | 2.96 |
Tools the pros use for this job
Laser Measure
Accurate wall-to-wall runs for a fabricator quote.
Template Material
Template awkward corners before the slab is cut.
Stone Sealer
Granite and marble tops need sealing; quartz does not.
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How this calculator works
Square feet = length (in) × depth (in) ÷ 144 for each piece. In an L or U, measuring both runs to the corner counts the corner square twice, so the calculator subtracts depth × depth once per inside corner. The backsplash is the wall-run length × splash height ÷ 144. In metric, cm × cm ÷ 10,000 gives m².
Slabs: fabricators cut tops from whole slabs, so the slab count matters more than the square footage. A common quartz slab is about 120 × 55 in (45.8 sq ft) and a jumbo slab about 130 × 65 in; granite varies by block. Seams, grain direction and cut-outs mean you rarely use more than about 80% of a slab, which is the default usable share.
- Standard base-cabinet counters are 25 to 25½ in deep, giving a 1 to 1½ in overhang over 24 in cabinets.
- For seating, the NKBA guidelines allow 24 in of counter width per person, with 15 in of knee space at a 36 in high counter and 12 in at 42 in.
- Sink and cooktop cut-outs are not subtracted: the stone is bought and cut from the full piece.
Tiling the backsplash instead? Use the backsplash tile calculator or the backsplash cost calculator.
Frequently asked questions
How do I calculate countertop square footage?
Multiply length by depth in inches and divide by 144. A 120 × 25.5 in run is 3,060 sq in, or 21.25 sq ft. Add each run and the island, then subtract one depth × depth square for every inside corner of an L or U.
How many square feet of countertop does an average kitchen have?
Many kitchens have 30 to 50 sq ft of counter. An L with 10 ft and 8 ft runs is about 34 sq ft before an island; a 6 × 3 ft island adds 18 sq ft.
How big is a quartz slab?
Standard quartz slabs are around 120 × 55 in (about 46 sq ft) and jumbo slabs around 130 × 65 in (about 59 sq ft). Ask your fabricator for the slabs of the colour you choose.
Do I include the backsplash in countertop square footage?
Yes if it is cut from the same stone. A 4 in splash along 18 ft of wall adds 6 sq ft; a full-height splash adds far more and may need another slab.
How much overhang does an island need for seating?
The NKBA guidelines call for 15 in of knee space at a 36 in counter and 12 in at a 42 in bar height, with 24 in of width per seat. A 72 in island seats three.
How do I calculate countertop area in square metres?
Switch to centimetres. Length × depth in cm ÷ 10,000 gives m²: a 305 × 65 cm run is 1.98 m².
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