Calculating Square Feet

Square Footage Calculator

Accurately measure area for flooring, paint, and renovation projects.

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Calculation Results:

Total Area: 0 sq ft
Estimated Material Cost: $0.00

How to Calculate Square Feet

Square footage is a measurement of area, typically used to determine the size of a room or a piece of land. Calculating it correctly is essential for purchasing materials like flooring, carpet, or sod, ensuring you don't overbuy or run short.

The Basic Formula

For a standard rectangular or square area, the formula is simple:

Length (ft) × Width (ft) = Total Square Feet (sq ft)

Dealing with Inches

Most rooms aren't measured in perfect foot increments. To calculate accurately with inches, you must first convert the inches to a decimal of a foot by dividing by 12.

  • Example: If a wall is 10 feet 6 inches long.
  • Divide 6 by 12 = 0.5.
  • Total Length = 10.5 feet.

Example Calculation

Imagine you are tiling a kitchen that is 12 feet 4 inches long and 10 feet wide.

  1. Convert Length: 4″ / 12 = 0.33. Total length = 12.33 ft.
  2. Multiply: 12.33 ft × 10 ft = 123.3 sq ft.
  3. Wastage: Usually, you should add 10% for cuts and mistakes. 123.3 × 1.10 = 135.63 sq ft total to order.

Common Measurements and Their Square Footage

Standard Room Average Dimensions Est. Sq Ft
Small Bathroom 5′ x 8′ 40 sq ft
Master Bedroom 14′ x 16′ 224 sq ft
Two-Car Garage 20′ x 20′ 400 sq ft
function calculateSquareFootage() { var lFt = parseFloat(document.getElementById('length_ft').value); var lIn = parseFloat(document.getElementById('length_in').value); var wFt = parseFloat(document.getElementById('width_ft').value); var wIn = parseFloat(document.getElementById('width_in').value); var pricePer = parseFloat(document.getElementById('price_per_sqft').value); // Validate inputs if (isNaN(lFt)) lFt = 0; if (isNaN(lIn)) lIn = 0; if (isNaN(wFt)) wFt = 0; if (isNaN(wIn)) wIn = 0; if (isNaN(pricePer)) pricePer = 0; // Convert everything to decimal feet var totalLength = lFt + (lIn / 12); var totalWidth = wFt + (wIn / 12); // Calculate Area var sqFt = totalLength * totalWidth; // Display Square Footage document.getElementById('total_area').innerHTML = sqFt.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); // Calculate and display cost if price > 0 if (pricePer > 0) { var totalCost = sqFt * pricePer; document.getElementById('total_cost').innerHTML = '$' + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); document.getElementById('cost_display').style.display = 'block'; } else { document.getElementById('cost_display').style.display = 'none'; } // Show the result container document.getElementById('sqft-results').style.display = 'block'; }

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