Square Footage Calculator
Calculate the square footage of a room or area from length and width measurements.
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About the Square Footage Calculator
Square footage is the basic unit of measurement behind flooring, paint, tile, and real estate — this calculator finds it instantly from a length and width, with a square meter conversion for anyone working in metric.
How It Works
The calculator multiplies length by width directly to get the area in square feet, then multiplies that by the standard conversion factor to also show the equivalent in square meters.
Square Footage = Length × Width; Square Meters = Square Footage × 0.092903.
For an L-shaped room, measure the outer length and width, then subtract the rectangular missing corner: area = outer length × outer width − cut-out length × cut-out width. The cut-out must be smaller than the outer rectangle in both directions.
Worked example
Scenario: A 12 ft × 10 ft room.
- Area: 12 × 10 = 120 square feet.
- In square meters: 120 × 0.0929 = 11.15 m².
Result: 120 sq ft (11.15 m²).
Tips and common mistakes
- For L-shaped rooms, choose L-shape and enter the outer rectangle plus the dimensions of the missing corner.
- Convert inches first: 12 ft 6 in = 12.5 ft.
- For flooring or tile, add waste with the Flooring or Tile Calculator.
Assumptions & Limitations
- Supports rectangular and L-shaped floor plans. L-shapes are modelled as one outer rectangle minus a corner cut-out; measure all dimensions in feet.
- Does not account for room features like closets, alcoves, or curved walls — measure each distinct rectangular section separately for accuracy.
From square footage to materials
Square footage tells you the size of a surface; it does not by itself tell you how much material to buy. Flooring, tile, paint, roofing and landscaping materials each have different coverage rates and waste considerations. Use square footage as the base measurement, then continue with the material-specific calculator so package sizes, depth, coats or waste can be handled correctly.