How to Calculate Sq Ft

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Square Footage Calculator

1. Measure Your Space

Enter the length and width of the area to determine total square footage.

2. Project Estimates (Optional)

0% (None) 5% (Standard) 10% (Recommended) 15% (Complex Patterns) 20% (Diagonal Lay)
Base Square Footage
0 sq ft

function calculateSquareFootage() { var lFt = parseFloat(document.getElementById('sqftLengthFt').value) || 0; var lIn = parseFloat(document.getElementById('sqftLengthIn').value) || 0; var wFt = parseFloat(document.getElementById('sqftWidthFt').value) || 0; var wIn = parseFloat(document.getElementById('sqftWidthIn').value) || 0; var price = parseFloat(document.getElementById('sqftPrice').value) || 0; var wastePercent = parseFloat(document.getElementById('sqftWaste').value) || 0; // Convert all to feet var totalLength = lFt + (lIn / 12); var totalWidth = wFt + (wIn / 12); var baseArea = totalLength * totalWidth; var wasteAmount = baseArea * (wastePercent / 100); var finalArea = baseArea + wasteAmount; var cost = finalArea * price; document.getElementById('baseSqFt').innerText = baseArea.toFixed(2) + " sq ft"; document.getElementById('wasteAdded').innerText = "Waste Factor (" + wastePercent + "%): +" + wasteAmount.toFixed(2) + " sq ft"; document.getElementById('totalWithWaste').innerText = "Total Material Required: " + finalArea.toFixed(2) + " sq ft"; if (price > 0) { document.getElementById('totalCost').innerText = "Estimated Total Cost: $" + cost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); } else { document.getElementById('totalCost').innerText = ""; } document.getElementById('sqftResult').style.display = 'block'; }

How to Calculate Square Footage: The Simple Formula

Calculating the square footage of a room is the first step for any home improvement project, whether you're installing hardwood flooring, painting walls, or laying carpet. The basic formula for a square or rectangular area is:

Length (ft) × Width (ft) = Square Footage (sq ft)

Steps to Measure Your Space

  1. Measure the Length: Use a tape measure to find the distance of one side of the room. If the measurement includes inches (e.g., 10 feet 6 inches), remember that 6 inches is 0.5 feet.
  2. Measure the Width: Measure the perpendicular side of the room in the same manner.
  3. Multiply the Two Numbers: Multiply the length by the width to get the total area.
  4. Account for Waste: Always add 10% to your final number to account for cuts, breakage, or mistakes during installation.

How to Calculate Irregular Shapes

Most homes aren't perfect rectangles. If you have an L-shaped room or a space with alcoves, follow the "Split and Sum" method:

  • Divide the area: Break the room into smaller, manageable rectangles.
  • Calculate each: Find the square footage for each individual rectangle.
  • Add them up: Sum the totals of all rectangles to find the total square footage of the entire space.

Real-World Example

Imagine you are tiling a kitchen that is 12 feet 6 inches long and 10 feet wide.

  • Length: 12.5 ft
  • Width: 10 ft
  • Calculation: 12.5 × 10 = 125 sq ft
  • With 10% Waste: 125 + 12.5 = 137.5 sq ft total to purchase.

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