What is Square Footage?
Square footage is a measurement of area expressed in square feet (sq ft or ft²). It is the most common unit of area measurement in the United States for real estate, construction, and home improvement projects. One square foot equals the area of a square that is one foot on each side, or 144 square inches.
Knowing the square footage of a space is essential for estimating materials (flooring, paint, tiles), comparing property sizes, calculating costs per square foot, and meeting building code requirements. Accurate square footage calculation saves money and prevents project delays.
Square Footage Formulas
Area Conversion Table
| From | To | Multiply By |
|---|---|---|
| Square Feet | Square Meters | 0.0929 |
| Square Feet | Square Yards | 0.1111 |
| Square Feet | Acres | 0.0000229568 |
| Square Meters | Square Feet | 10.764 |
Worked Example
A room measuring 20 ft by 15 ft:
= 27.87 m² = 33.33 sq yd
Frequently Asked Questions
How do I calculate square footage of an irregular shape?
Break the irregular shape into rectangles, triangles, and circles. Calculate each section separately, then add them together. For very irregular shapes, measure the longest and widest points and use the rectangle formula for a rough estimate.
What is the difference between square footage and linear footage?
Square footage measures area (two dimensions: length × width), while linear footage measures only length (one dimension). You need square footage for flooring and paint estimates, but linear footage for molding, fencing, and countertops.
How many square feet in an acre?
One acre equals 43,560 square feet, which is roughly the size of a football field (without end zones).