Room Size Calculator

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Room Size & Square Footage Calculator

Feet (ft) Meters (m)
Rectangular / Square L-Shaped Room

Primary Area Dimensions

Secondary Area Dimensions (L-Shape)

$
Total Room Area:
0 sq ft
Perimeter: 0 ft
Estimated Material Cost: $0.00
function toggleLshape() { var shape = document.getElementById("roomShape").value; var lSection = document.getElementById("lShapeInputs"); var title = document.getElementById("section1Title"); if (shape === "lshape") { lSection.style.display = "block"; title.innerText = "Primary Area Dimensions (Section A)"; } else { lSection.style.display = "none"; title.innerText = "Primary Area Dimensions"; } } function calculateRoomSize() { var unit = document.getElementById("roomUnit").value; var shape = document.getElementById("roomShape").value; var l1 = parseFloat(document.getElementById("length1").value) || 0; var w1 = parseFloat(document.getElementById("width1").value) || 0; var price = parseFloat(document.getElementById("pricePerUnit").value) || 0; var totalArea = 0; var totalPerimeter = 0; var unitText = (unit === "feet") ? "sq ft" : "sq m"; var pUnitText = (unit === "feet") ? "ft" : "m"; if (shape === "rect") { totalArea = l1 * w1; totalPerimeter = 2 * (l1 + w1); } else { var l2 = parseFloat(document.getElementById("length2").value) || 0; var w2 = parseFloat(document.getElementById("width2").value) || 0; totalArea = (l1 * w1) + (l2 * w2); // Simple L-shape perimeter assumes internal corner, common approximation: // Perimeter = Sum of outer boundaries. For calculation simplicity: totalPerimeter = 2 * (l1 + w1) + 2 * (l2 + w2); } if (totalArea > 0) { document.getElementById("roomResult").style.display = "block"; document.getElementById("areaOutput").innerText = totalArea.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}) + " " + unitText; document.getElementById("perimeterOutput").innerText = "Estimated Perimeter: " + totalPerimeter.toLocaleString() + " " + pUnitText; if (price > 0) { var totalCost = totalArea * price; document.getElementById("costOutput").style.display = "block"; document.getElementById("costOutput").innerText = "Estimated Material Cost: $" + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); } else { document.getElementById("costOutput").style.display = "none"; } } else { alert("Please enter valid length and width dimensions."); } }

How to Use the Room Size Calculator

Whether you are planning to install new hardwood flooring, paint a bedroom, or buy a rug that actually fits, knowing the exact square footage of your space is essential. This room size calculator simplifies the math for both standard rectangular rooms and more complex L-shaped layouts.

Step-by-Step Measurement Guide

  1. Choose Your Units: Select between Imperial (Feet) or Metric (Meters).
  2. Select Room Shape: Choose "Rectangular" for standard four-walled rooms. Choose "L-Shaped" if your room has an alcove or an extra section.
  3. Input Dimensions: Measure the length and width of the floor space. If L-shaped, divide the room into two imaginary rectangles and measure both.
  4. Material Cost (Optional): If you know the price per square foot of your flooring or carpet, enter it to see an instant budget estimate.

The Math Behind the Calculation

For a standard room, we use the basic geometric formula for area:

Area = Length × Width

If you have an L-shaped room, the calculator treats it as two distinct rectangles (A and B) and adds them together:

Total Area = (Length A × Width A) + (Length B × Width B)

Practical Examples

  • Master Bedroom: A 12ft by 15ft room equals 180 sq ft.
  • Small Kitchen: A 3m by 4m space equals 12 sq m.
  • Studio Apartment: If the main area is 20×15 and the hallway/nook is 5×4, the total is 300 + 20 = 320 sq ft.

SEO Tips: Why Accuracy Matters

Underestimating your room size can lead to project delays, while overestimating can result in wasted money on excess materials. When purchasing flooring, it is standard industry practice to add 10% extra to your total square footage to account for cutting waste and mistakes. For example, if your result is 200 sq ft, you should ideally order 220 sq ft of material.

Frequently Asked Questions

How do I measure a room with many angles?
Break the room down into smaller rectangles or triangles. Calculate the area of each and sum them up. Our L-shaped option is a great start for rooms that aren't perfect squares.

Does perimeter matter for flooring?
Yes! While square footage tells you how much flooring you need, the perimeter tells you how many linear feet of baseboards or trim you need to purchase.

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