Square Footage Calculator
Square footage = length in feet x width in feet. Inches are converted to feet first.
Enter feet and inches
Enter the length and width of the room or section in feet. If you have inches, convert them to decimal feet or use a feet and inches input if available.
For an irregular room, split the floor into rectangles, triangles or other simple sections. Calculate each section and add the square footage together.
Use this for flooring, paint estimates, rugs, real estate sketches and quick layout planning. For material orders, add waste based on the material and installation pattern.
Reading total square feet
Square footage is area measured in square feet. A room that is 10 feet by 12 feet has 120 square feet.
The result describes surface area, not the length of walls and not the amount of material after cuts.
If you are buying flooring, the calculated square footage is the starting point. Waste, cuts, damaged pieces and pattern matching can increase the amount to buy.
Converting inches to feet
For a rectangle, square footage = length in feet x width in feet. For feet and inches, convert inches into a fraction of a foot by dividing by 12.
For example, 10 feet 6 inches is 10.5 feet. Then multiply by the other dimension.
For multiple sections, calculate each section separately and add the totals. Subtract closets, cutouts or missing areas only when they should not be included.
Room square footage example
A room that is 13 feet long and 9 feet wide has 13 x 9 = 117 square feet.
If a room is 10 feet 6 inches by 8 feet, convert 6 inches to 0.5 feet. Then calculate 10.5 x 8 = 84 square feet.
For an L shaped room, split it into two rectangles. Add the two rectangle areas for the total.
Measuring irregular rooms
The biggest mistake is treating inches as decimals. 10 feet 6 inches is 10.5 feet, not 10.6 feet.
Another mistake is measuring wall length when the project needs floor area. Square footage needs two perpendicular dimensions.
Also avoid forgetting waste for materials. The calculator gives area. The final purchase amount may need extra for cuts and mistakes.
Measure each room separately before combining totals. It is easier to find and fix one room mistake than a whole house total.
Square Footage Calculator FAQ
How do I calculate square footage of a room?
Measure the length and width in feet. Multiply length by width.
For a 12 foot by 15 foot room, the square footage is 180 square feet.
If the room is not rectangular, split it into smaller shapes and add the areas.
How do I handle feet and inches?
Convert inches to feet by dividing by 12. Six inches is 0.5 feet. Three inches is 0.25 feet.
Then add that decimal to the whole feet before multiplying.
This avoids the common mistake of reading 8 feet 6 inches as 8.6 feet.
How do I calculate an irregular room?
Draw the room and split it into rectangles or triangles. Measure each section separately.
Calculate the area of each section, then add them together.
If a section is missing, such as a cutout, subtract that area from the larger shape.
Should I add extra square footage for flooring?
Usually yes. Flooring projects often need extra material for cuts, waste, mistakes and future repairs.
The exact percentage depends on the material, layout and installer guidance. Straight layouts may need less extra than diagonal or patterned layouts.
Use the calculator result as the measured area, then add the waste allowance separately.
Is square footage the same as room size?
Square footage is one way to describe room size, but it does not show shape, ceiling height or usable layout.
Two rooms can have the same square footage and feel very different if one is narrow and the other is more balanced.
For furniture planning, also check the actual length and width.
For buying materials, square footage is useful. For designing the room, dimensions still matter.