Square Footage Calculator
Add up the square feet of one room or several, measured in feet and inches, with square yards, square meters, a waste allowance and the cost at your price per square foot.
Multiply a room's length by its width, both in feet, after turning inches into feet by dividing by 12, so 12 ft 6 in is 12.5 ft. A room 12.5 ft by 10 ft covers 12.5 × 10 = 125 square feet, and one 14 ft by 11 ft 3 in covers 14 × 11.25 = 157.5, for 125 + 157.5 = 282.5 square feet in all. With a 10 percent allowance you choose for cuts, that is 282.5 × 1.1 = 310.75 square feet.
Results assume each room or area is a rectangle measured in feet, with inches converted by dividing by 12. Areas are rounded to two decimals and costs to the cent for display. Check the waste figure and price with your supplier before ordering materials.
Split an L-shaped or irregular room into rectangles and enter each one as its own area. Inches run from 0 to under 12; each side can be up to 10,000 ft.
Total floor area
282.50 sq ft
- Room 1
- 125.00 sq ft
- Room 2
- 157.50 sq ft
- Square yards
- 31.39 sq yd
- Square meters
- 26.25 m²
- With 10% waste
- 310.75 sq ft
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About the Square Footage Calculator
Measure each room wall to wall at floor level and write down feet and inches separately; the calculator converts inches to feet by dividing by 12 before it multiplies, so 10 ft 6 in counts as ten and a half feet rather than as if the 6 were tenths. An L-shaped room is two rectangles that do not overlap, so measure it as two areas and the totals add up. Square yards divide the square feet by 9, because a yard is 3 feet on each side, and square meters use the exact inch of 2.54 centimeters, which makes one square foot 0.09290304 square meters. The waste allowance is a figure you choose to cover offcuts, pattern matching and spare pieces; the calculator adds it as a percentage of the floor area and does not assume one for you. Enter a price per square foot and it multiplies both the floor area and the area with waste, so you can compare the two totals before you order. Closets, alcoves and stair landings count only if the material runs into them.
Frequently asked questions
How do I calculate square footage with inches?+
Divide the inches by 12 and add them to the feet before you multiply. A wall of 11 ft 3 in is 11.25 ft, because 3 / 12 = 0.25. A room 14 ft by 11 ft 3 in is 14 × 11.25 = 157.5 square feet.
How do I find the square footage of an L-shaped room?+
Split it into two rectangles along one of the inside corners, measure each, and add the two areas. Set Rooms or areas to 2 and enter each rectangle on its own. Any split works as long as the two pieces cover the room exactly, with no overlap and no gap.
How much extra flooring should I buy?+
That depends on the material, the room's shape and the pattern you lay, so the calculator leaves the percentage to you. The installation instructions or your supplier can give the figure they use. At 282.5 square feet, a 10 percent allowance adds 282.5 × 0.1 = 28.25 square feet, for 310.75 in total.
How do I work out the cost?+
Enter the price per square foot and the calculator multiplies it by the area. At $4.25 a square foot, 282.5 square feet costs $1,200.63, and 310.75 square feet with waste costs $1,320.69. Labor, underlayment and trim are priced separately, so add them on top.
Why is 12 ft 6 in written as 12.5 ft?+
A foot has 12 inches, not 10, so 6 inches is half a foot: 6 / 12 = 0.5. Reading the inches as if they were tenths overstates the length and every area built on it. Enter feet and inches in their own boxes and the calculator does the conversion. For circles, triangles and other shapes, use the area calculator.
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