Kitchen Countertop Square Footage: L-Shaped Layouts, Overhangs, and Backsplash
October 29, 2026
Countertops are priced by the square foot, so an accurate measurement matters. Standard kitchen base cabinets are 24 inches deep and counters add a 1-inch overhang, making a depth of 25 inches. For straight runs, area is length × depth ÷ 144 in square feet. For an L-shaped kitchen, the corner is the part where people double count, so measure one leg at its full length and the other leg excluding the corner depth.
As an example, one leg is 96 inches long, and the other is 60 inches long measured along the wall. The first leg is 96 × 25 = 2,400 square inches. The second leg, excluding the corner already counted, is (60 − 25) × 25 = 875 square inches. The total is 3,275 square inches, or 22.7 square feet.
Skip the math and get your answer instantly:
Open the Area Calculator →Measuring Step by Step
1. Draw a sketch of the layout with each run. 2. Measure the length of each run along the back wall, including to the end of any overhang. 3. Decide on the depth: 25 inches is standard, 25.5 with a thick edge profile, and islands commonly need 36 inches or more, with a seating overhang of 12 inches. 4. Compute each piece's area and sum them. 5. Subtract sink and cooktop cutouts only if the material is sold as a custom piece; fabricators generally charge for the full slab area because cutouts are waste. 6. Add 10% to 15% for waste and seams.
For the L-shape example, 22.7 square feet plus 10% is 25 square feet. An island of 4 by 2 feet (8 square feet) would add to that.
| Piece | Dimensions | Area |
|---|---|---|
| Leg 1 | 96 in x 25 in | 16.7 sq ft |
| Leg 2 (corner excluded) | 35 in x 25 in | 6.1 sq ft |
| Total countertop | 22.7 sq ft | |
| With 10% waste | 25.0 sq ft | |
| Backsplash (4 in high, 156 in run) | 4.3 sq ft |
Backsplash
A full-height tile backsplash runs from the countertop up to the wall cabinets, typically 18 inches high. For the 156 inches of wall in the example, a 4-inch splash is 156 × 4 ÷ 144 = 4.3 square feet, while an 18-inch tile backsplash covers 156 × 18 ÷ 144 = 19.5 square feet, minus windows and the range hood area. Tile needs 10% to 15% waste, with extra for diagonal patterns. Many fabricators supply a matching 4-inch splash. Subtract outlets, but they still require cut tiles.
Comparing Materials
Typical installed prices (which vary widely by region): laminate $20 to $50 per square foot, butcher block $40 to $80, solid surface $50 to $100, granite $50 to $120, quartz $60 to $150, and marble $75 to $200 or more. For 25 square feet, laminate might cost $500 to $1,250, quartz $1,500 to $3,750. Compare durability, maintenance (granite and marble need sealing; quartz does not), heat and scratch resistance, and appearance. Slab sizes limit the layout: quartz slabs are usually about 120 × 55 inches, so layouts that fit on one slab with minimal seams cost less. Ask the fabricator to lay out your pieces on the slab.
Templates and Timing
Final measurements are done by the fabricator after the cabinets are installed, because walls are rarely straight. Do not order stone before cabinets are in place. Lead times of 1 to 3 weeks after templating are common. Confirm sink type (undermount, drop-in), faucet holes, and edge profile in advance. Verify that the cabinets can support the weight: stone weighs about 13 pounds per square foot at 3 cm thickness.
Frequently Asked Questions
How do I calculate countertop square footage?
Length times depth in inches divided by 144, summed over all runs, counting corners once.
What is the standard countertop depth?
25 inches, including a 1-inch overhang over 24-inch cabinets.
Do I pay for sink cutouts?
Usually yes, because the cutout is waste from the slab.
How much extra should I allow?
About 10% to 15% for waste and seams.
How heavy is a stone countertop?
About 13 pounds per square foot for 3 cm granite or quartz.