This square footage calculator converts room or lot dimensions into square feet or square meters for real estate and renovation math.
Construction
Square Footage Calculator
Calculate total area and material cost for one or more rectangles.
Calculator
About this calculator
Formula notes
area = length × width; for L-shapes, split into rectangles and add the areas.
Worked examples
- Example: a 20 ft × 10 ft room is 200 ft² ≈ 18.58 m².
- Two rectangles measuring 12 ft x 10 ft and 6 ft x 4 ft total 144 ft2; at $3.50 per ft2, material cost starts at $504 before waste.
How to use it
- Enter the length and width of the space.
- Add sections for irregular shapes.
- Read the total square footage.
Frequently asked questions
How do I handle an L-shaped room?
Split it into two rectangles, compute each area, and add them.
Is square footage measured inside walls?
Real-estate figures usually use interior dimensions; confirm the local convention.
Limits and interpretation
- Overlapping rectangles must not be counted twice, while excluded openings or voids must be subtracted separately.
- Linear measurements need consistent units and realistic field precision before they are multiplied into area.