Square footage is the measure of an area, useful for flooring, paint, rugs, and real estate. For a rectangular space you multiply length by width, and larger or oddly shaped areas can be broken into rectangles and added together.
What you'll need
- A tape measure
- A calculator
- Paper and pen for notes
Step by step
- Measure the length in feetMeasure the longer dimension of the space from wall to wall in feet. Convert any inches to a decimal by dividing by 12.
- Measure the width in feetMeasure the shorter dimension the same way, again converting leftover inches to a decimal fraction of a foot.
- Multiply length by widthMultiply the two measurements together. A room 12 feet by 10 feet gives 120 square feet.
- Split irregular spaces into sectionsFor an L-shaped or uneven room, divide it into rectangles, find the square footage of each, and add the results together.
- Add a little extra for materialsWhen buying flooring or tile, add about 5 to 10 percent to your total to cover cuts, waste, and mistakes.
Handy tips
- Always measure in feet, or convert inches to feet by dividing by 12 before multiplying.
- Sketch the room and label each measurement so you do not lose track of sections.
- For circular areas, square footage equals 3.14 times the radius times the radius.
FAQ
How do I calculate square feet from inches?
Convert each measurement to feet first by dividing the inches by 12, then multiply length by width. You can also multiply inches together and divide by 144.
How do I find square footage of a non-rectangular room?
Break the space into rectangles and triangles, calculate each piece separately, and add them up for the total area.
How much extra material should I buy?
A common rule is to add 5 to 10 percent to your measured square footage to account for waste, cuts, and future repairs.