1. Measure each section
Use a tape measure to record the length and depth of each straight countertop section in feet or inches. Include any island or peninsula sections separately.
What is countertop square footage?
Countertop square footage is the total surface area of a countertop measured in square feet. To calculate countertop square footage, measure the length and depth of each countertop section in inches, multiply to get square inches, then divide by 144. Most kitchen countertops have a standard depth of 25.5 inches. For L-shaped or U-shaped kitchens, measure each straight section separately and add the areas together.
Getting started
How to Calculate Countertop Square Footage
To calculate countertop square footage, measure each straight section of countertop. Record the length along the wall and the depth from the wall to the front edge. Multiply length by depth to get the area. For L-shaped kitchens, measure each arm of the L separately and add the areas together.
2. Select your shape
Choose Rectangle for a single straight section, or L-Shape for countertops that wrap around a corner. Enter dimensions for each section.
3. Get area and cost
View total countertop area in square feet. Enter a price per square foot for granite, quartz, marble, or laminate to estimate total material and installation cost.
Quick reference
Reference
1 acre = 43,560 square feet
1 square yard = 9 square feet
1 square meter = 10.764 square feet
1 square inch = 0.00064516 square feet
Core formula
Basic Formula for Area
Area is the amount of space occupied by a 2-dimensional shape. The shape could be a floor, a wall, a playground, or a field. The simplest formula for area applies to any rectangular shape:
Area = Length × Width
Measure the length and width of the space in feet. Multiply the two values to get the area in square feet. A rectangular room that is 12 feet (3.66 meters) long and 10 feet (3.05 meters) wide has an area of 120 sq ft (11.15 sq m).
Square yardage is area measured in yards, and square meters is area measured in meters. Measure in feet, find the area in square feet, then convert to the unit you need.
For an L-shape room, split the floor into 2 rectangular sections, calculate each area, and add the results. Convert all measurements to the same unit before multiplying, if your dimensions are in different units like inches and feet.
Shape formulas
Area Formulas for Countertops
The Countertop Calculator uses the rectangle formula to calculate surface area for straight countertop sections.
Rectangle Shape
Calculate countertop surface area
Using measurements in feet: Area (ft²) = Length × Depth. A countertop 8 feet long and 2.125 feet deep (25.5 inches) has 17 square feet of surface area. Measure each straight section separately and add for L-shaped or U-shaped countertops.
Waste factor
Adding 10% Surplus for Materials
Add a 10% surplus to your calculated area to account for material waste during cutting, breakage, and pattern matching. This waste factor applies to flooring, carpet, tiling projects, and landscaping materials.
Original Area100 sq ft
+10%
Order Amount110 sq ft
Total Material = Area × 1.10
A room with 200 sq ft of floor area needs 220 sq ft of material: 200 × 1.10 = 220 sq ft. Increase the surplus to 15% (multiply by 1.15) for diagonal flooring installation patterns or complex tiling projects with many cuts. The Square Foot Calculator includes a waste factor field for this calculation.
FAQ
Frequently Asked Questions
How do I measure countertop square footage?
Measure each straight section of countertop in inches (length and depth), multiply to get square inches, then divide by 144 to convert to square feet. Add all sections together. A countertop section 96 inches long and 25.5 inches deep is 2,448 sq in or 17 sq ft.
How many square feet is a typical kitchen countertop?
A typical kitchen countertop ranges from 25 to 50 square feet, depending on the kitchen layout. An average L-shaped kitchen has about 30-40 sq ft of countertop surface.
How much does granite cost per square foot?
Granite countertops cost $40 to $100 per square foot installed, depending on the stone grade and edge profile. Budget granite starts at $40/sq ft, mid-range at $50-75/sq ft, and premium exotic granite at $75-100+ per sq ft.
How do I calculate an L-shaped countertop?
Split the L-shaped countertop into two rectangular sections. Measure the length and depth of each section, calculate the area of each, and add them together. Use the L-Shape option in the calculator.
What is the standard countertop depth?
Standard kitchen countertop depth is 25 to 25.5 inches (about 2.125 feet). Island countertops may be deeper at 27 to 30 inches. Bathroom vanity countertops are typically 22 inches deep.
How much does quartz cost per square foot?
Quartz countertops cost $50 to $120 per square foot installed. Entry-level quartz starts at $50/sq ft, mid-range at $65-85/sq ft, and premium brands at $85-120/sq ft.