How to Calculate Countertop Square Footage

Enter the dimensions of your countertop sections in inches:

Results:

Total Square Inches: 0 sq in

Total Square Footage: 0 sq ft

Estimated Material Cost: $0.00

function calculateCountertop() { var l1 = parseFloat(document.getElementById('len1').value) || 0; var w1 = parseFloat(document.getElementById('wid1').value) || 0; var l2 = parseFloat(document.getElementById('len2').value) || 0; var w2 = parseFloat(document.getElementById('wid2').value) || 0; var l3 = parseFloat(document.getElementById('len3').value) || 0; var w3 = parseFloat(document.getElementById('wid3').value) || 0; var cost = parseFloat(document.getElementById('costPerSqFt').value) || 0; var sqIn1 = l1 * w1; var sqIn2 = l2 * w2; var sqIn3 = l3 * w3; var totalInches = sqIn1 + sqIn2 + sqIn3; var totalFeet = totalInches / 144; document.getElementById('totalSqIn').innerText = totalInches.toLocaleString(undefined, {minimumFractionDigits: 0, maximumFractionDigits: 2}); document.getElementById('totalSqFt').innerText = totalFeet.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); if (cost > 0) { var totalMaterialCost = totalFeet * cost; document.getElementById('totalCost').innerText = '$' + totalMaterialCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); document.getElementById('costEstimateRow').style.display = 'block'; } else { document.getElementById('costEstimateRow').style.display = 'none'; } document.getElementById('countertopResult').style.display = 'block'; }

How to Calculate Countertop Square Footage

Calculating the square footage of your countertops is a crucial step in budgeting for a kitchen remodel or bathroom upgrade. Whether you are installing granite, quartz, laminate, or butcher block, material pricing is almost always based on the total square foot (sq ft) area.

The Step-by-Step Calculation Formula

Because countertops are rarely one single rectangle, you must break your layout into manageable sections. Use this simple formula for each section:

1. Measure the Length: Use a tape measure to find the length of the section in inches.
2. Measure the Width: Measure from the wall to the front edge (standard base cabinets are usually 24″ deep, but countertops usually have a 1.5″ overhang, making them 25.5″ wide).
3. Multiply: Length (in) × Width (in) = Total Square Inches.
4. Convert to Square Feet: Divide the total square inches by 144 (since there are 144 square inches in one square foot).

Example Calculation

Imagine you have a main counter that is 100 inches long and a standard 25.5 inches wide, plus a small island that is 40 inches by 30 inches.

• Section 1: 100″ × 25.5″ = 2,550 sq in
• Section 2: 40″ × 30″ = 1,200 sq in
• Total Inches: 2,550 + 1,200 = 3,750 sq in
• Total Feet: 3,750 / 144 = 26.04 sq ft

Important Tips for Accuracy

Component	Standard Dimension
Standard Depth	25.5 inches (includes 1.5″ overhang)
Backsplash Height	Usually 4 inches (if using same material)
Waste Factor	Add 10% for cuts and corners

Don't Forget the Details

When calculating for a professional quote, keep in mind that fabricators also charge for "linear feet" of edge treatments (like bullnose or bevel edges) and specific cutouts for sinks and cooktops. While the square footage gives you the material cost, these labor-intensive additions will affect the final price.