How to Calculate Countertop Sq Ft

Countertop Square Footage Calculator

Use this calculator to estimate the total square footage of your kitchen or bathroom countertops. Break your layout into rectangular sections for the most accurate result.

Section 1: Main Counter

Section 2: Island or Additional Counter

Section 3: Backsplash

Estimate Options

0% 5% (Recommended) 10% (Standard) 15% (Complex Cuts)

Measurement Summary

Net Surface Area

0 sq ft

Total with Waste

0 sq ft

Estimated Material Cost

$0.00

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How to Calculate Countertop Square Footage

Whether you are planning a DIY renovation or getting quotes from contractors, knowing how to accurately measure your countertops is the first step in budgeting. Countertop material is almost always priced by the square foot (sq ft).

The Basic Formula

To find the square footage of any rectangular section, use this formula:

(Length in Inches × Width in Inches) / 144 = Square Footage

Since there are 144 square inches in a square foot (12″ x 12″), we divide the total cubic inches by 144 to get the final area.

Step-by-Step Measuring Guide

1. Divide the Area: Split your countertop into simple rectangles. For example, an L-shaped kitchen should be measured as two separate rectangles.
2. Measure Length: Measure along the back wall for each section. Include any overhangs (standard is 1.5 inches past the cabinet base).
3. Measure Depth: Standard kitchen countertops are usually 25 to 25.5 inches deep. Islands vary greatly, often ranging from 36 to 42 inches.
4. Calculate Backsplash: If you are using the same material for the backsplash, measure its total length and the height (standard 4-inch or full height).
5. Add Waste Factor: Always add 10% to your total to account for seams, cuts, and potential breakage.

Example Calculation

Imagine you have a main counter that is 96 inches long and 25.5 inches deep, plus an island that is 72 inches long and 36 inches deep.

• Main Section: (96 × 25.5) / 144 = 17.00 sq ft
• Island Section: (72 × 36) / 144 = 18.00 sq ft
• Subtotal: 35.00 sq ft
• With 10% Waste: 35.00 × 1.10 = 38.50 sq ft

Common Countertop Depths

Application	Standard Depth
Standard Kitchen	25″ – 26″
Bathroom Vanity	19″ – 22″
Bar Counter	12″ – 18″

function calculateCountertop() { // Get inputs 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 wasteFactor = parseFloat(document.getElementById("wasteFactor").value) || 0; var pricePerSqFt = parseFloat(document.getElementById("pricePerSqFt").value) || 0; // Calculations var area1 = (l1 * w1) / 144; var area2 = (l2 * w2) / 144; var area3 = (l3 * w3) / 144; var netAreaTotal = area1 + area2 + area3; var grossAreaTotal = netAreaTotal * (1 + wasteFactor); // Display results document.getElementById("resultsArea").style.display = "block"; document.getElementById("netArea").innerText = netAreaTotal.toFixed(2); document.getElementById("totalArea").innerText = grossAreaTotal.toFixed(2); // Cost calculation if (pricePerSqFt > 0) { var totalCost = grossAreaTotal * pricePerSqFt; document.getElementById("costDisplay").style.display = "block"; document.getElementById("totalCost").innerText = "$" + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); } else { document.getElementById("costDisplay").style.display = "none"; } }