Our Calculator

Square Footage Calculator

Calculate the square footage of a rectangular room, floor or wall. Enter length and width in feet to see square feet, square yards and square meters.

No signup requiredMethod and rounding explainedEditorial standards and sources

Enter length and width

Measure both dimensions in feet for the square-foot result.

ft
ft
Your result

Square footage

Updates automatically as you change the inputs.

Area
120 sq ft
Square yards13.3333
Square meters11.1484
Perimeter44 ft

How to use the square footage calculator

Measure the rectangular area's length and width in feet, then multiply them. For irregular spaces, split the area into rectangles, calculate each one, and add the results.

Square footage formula

Calculation formulaSquare footage formula
Used for the result above
Square feet = length in feet × width in feet.

Square footage measures area, not linear length. A 12-foot by 10-foot room has 120 square feet of floor area.

Example: Oliver measures a room

Oliver measures a rectangular room as 15 feet long and 12 feet wide. Its floor area is 15 × 12 = 180 square feet, equivalent to 20 square yards.

For an L-shaped room, split it into non-overlapping rectangles and add their areas. Add a separate allowance for cuts and waste when ordering materials.

Convert inches into decimal feet

For a room measuring 12 feet 6 inches by 10 feet, enter 12.5 and 10. The area is 125 square feet.

For an L-shaped room, split it into rectangles and add their areas. Subtract openings separately and allow for material waste when estimating an order.

Measure an L-shaped floor without double counting

Divide the floor into separate rectangles and add their areas. A 12-by-10-foot section plus a 6-by-4-foot section totals 120 + 24 = 144 square feet.

Alternatively, measure the enclosing rectangle and subtract the missing section. A material allowance is added after finding the measured area: 144 square feet plus 10% is 158.4 square feet. The calculator does not add a waste allowance automatically.

Assumptions and limitations

What the estimate assumes

This calculator assumes a rectangle and does not add material waste, openings, or installation allowances.

Square Footage Calculator FAQs

How do I calculate square feet?

Multiply length in feet by width in feet.

How do I handle inches?

Convert inches to decimal feet first, or divide the inch measurement by 12.

How many square feet are in a square yard?

One square yard equals 9 square feet.

Should I add extra material for flooring?

Usually yes, but the appropriate waste allowance depends on the material, pattern, room shape, and installer.

How do I calculate square footage of an L-shaped room?

Divide the room into non-overlapping rectangles, calculate each rectangle's area, and add the results.

Measurement aid only. Verify dimensions and material allowances before purchasing or construction.