Linear Foot to Square Feet Calculator

Linear Foot to Square Feet Calculator

Convert length measurements into surface area quickly and accurately.

Calculation Results:

Total Square Footage: 0 sq. ft.

Total Estimated Cost: $0.00

function calculateSqFt() { var lf = parseFloat(document.getElementById('linearFeetInput').value); var widthInches = parseFloat(document.getElementById('widthInchesInput').value); var cost = parseFloat(document.getElementById('costPerSqFtInput').value); var resultArea = document.getElementById('resultArea'); var costRow = document.getElementById('costRow'); if (isNaN(lf) || isNaN(widthInches) || lf <= 0 || widthInches 0) { var totalCost = sqFt * cost; document.getElementById('totalCostResult').innerText = "$" + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); costRow.style.display = 'flex'; } else { costRow.style.display = 'none'; } resultArea.style.display = 'block'; }

Understanding Linear Foot to Square Feet Conversions

Whether you are planning a DIY flooring project, purchasing lumber for a deck, or installing new baseboards, understanding the difference between linear feet and square feet is critical for accurate material ordering and budgeting.

Linear Feet vs. Square Feet: What's the Difference?

Linear Feet is a measurement of length in a straight line. It only accounts for one dimension. For example, a 10-foot long board is exactly 10 linear feet, regardless of how wide it is.

Square Feet is a measurement of area (two dimensions). It accounts for both the length and the width of an object. To calculate square footage, you must know how wide the material is.

The Conversion Formula

To convert linear feet to square feet, use the following formula:

Square Feet = Linear Feet × (Width in Inches ÷ 12)

Practical Examples

• Hardwood Flooring: If you have a plank that is 6 inches wide and you have 100 linear feet of it, the calculation is 100 × (6 / 12) = 50 square feet.
• Decking Boards: A standard 2×6 board is actually 5.5 inches wide. If you have 50 linear feet of 2×6, the area covered is 50 × (5.5 / 12) = 22.92 square feet.
• Countertops: If you have a 10-foot long countertop that is 24 inches deep, the calculation is 10 × (24 / 12) = 20 square feet.

Why This Calculation Matters

Materials like trim, molding, and fencing are usually sold by the linear foot. However, coatings like stain, paint, or sealant are sold by their square foot coverage. Using this calculator ensures you buy exactly the amount of finishing product you need for the surface area you have measured in linear distance.

Common Width Conversions

Nominal Width	Actual Width (Inches)	Sq. Ft. per Linear Foot
1×4 Board	3.5″	0.291
1×6 Board	5.5″	0.458
1×8 Board	7.25″	0.604
1×12 Board	11.25″	0.937