Square Footage Calculator
Calculate area in square feet and square meters for rectangles, circles, triangles, and L-shapes.
Enter outer rectangle, then the cutout rectangle removed from one corner.
Area
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Square Meters
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Perimeter
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What is Square Footage Calculator?
The Square Footage Calculator computes the area of a room or surface in square feet and square meters. It supports four common shapes: rectangle, circle, triangle, and L-shape. It also calculates the perimeter so you can estimate flooring, paint, or fencing needs.
How to use
- 1 Select the shape of the area you want to measure.
- 2 Enter the required dimensions for that shape (e.g., length and width for a rectangle).
- 3 Click Calculate to get the area in square feet and square meters.
- 4 Use the perimeter value to estimate baseboard, trim, or fencing material.
- 5 For an L-shape, enter the outer dimensions and the cutout dimensions.
Formula
Example calculation
A rectangular room 12 ft × 15 ft = 180 sq ft = 16.72 m². Perimeter = 2 × (12 + 15) = 54 ft.
Frequently asked questions
How do I measure an irregular room?
Break the room into rectangles and add the areas together. The L-shape mode does this automatically for rooms with one rectangular cutout.
How many square feet are in a square meter?
1 square meter = 10.764 square feet. The calculator converts automatically.
How much flooring do I need?
Calculate the square footage and add 10% for waste and cuts, especially with diagonal or patterned installations.
What is the perimeter used for?
Perimeter is useful for estimating baseboard trim, crown molding, fencing, or the amount of edging needed around a garden bed.
Can I use this for outdoor areas?
Yes — the same formulas apply to yards, patios, gardens, driveways, and any other flat surface.