Free tool for contractors
Square footage calculator
Enter length and width in feet and inches. Add rooms, waste and a price per square foot.
Step by step
How to calculate square footage
Measure the space
Length and width of each room or area, in feet and inches.
Enter each area
Pick rectangle, circle or triangle and type the sizes. Add a row per room.
Add waste
Add a percentage for cuts and breakage when you are ordering material.
Add a price
Type a price per square foot to see what the job or the material costs.
Print the list
Print every area and the total, or save it as a PDF.
What it does
A square foot calculator for rooms, flooring and job quotes
A sq ft calculator for any space: one room or a whole house, in feet and inches, with square yards and square meters beside the total.
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Feet and inches
Type 12 ft 6 in as it reads on the tape. No converting first.
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Room by room
Add every room or area and get one total.
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Rectangles, circles, triangles
Split an odd-shaped room into simple shapes and add them.
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Waste allowance
Add a percentage for cuts, so you order enough flooring or tile.
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Price per square foot
Turn the area into a material cost or a job price.
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Square yards, meters, acres
The same area in the unit your supplier uses.
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Print or PDF
A one-page list of each area and the total.
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Free and private
No sign-up. Your measurements stay in your browser.
The formulas
How square feet are calculated
- Rectangle or square: length × width. 12 ft × 10 ft = 120 sq ft.
- Feet and inches: inches ÷ 12 are added to the feet first. 12 ft 6 in is 12.5 ft.
- Circle: 3.1416 × radius × radius. A circle 10 ft across is 78.5 sq ft.
- Triangle: base × height ÷ 2.
- Square yards: square feet ÷ 9. Square meters: square feet × 0.0929.
- With waste: area × (1 + waste %). 200 sq ft with 10% waste is 220 sq ft to order.
Pouring a slab on that area? The concrete calculator turns it into cubic yards and bags.
Square footage of common room sizes
| Room | Sq ft | Sq yd | Sq m |
|---|---|---|---|
| 10 × 10 ft | 100 | 11.1 | 9.3 |
| 10 × 12 ft | 120 | 13.3 | 11.1 |
| 12 × 12 ft | 144 | 16 | 13.4 |
| 12 × 15 ft | 180 | 20 | 16.7 |
| 15 × 15 ft | 225 | 25 | 20.9 |
| 15 × 20 ft | 300 | 33.3 | 27.9 |
| 20 × 20 ft | 400 | 44.4 | 37.2 |
| 20 × 30 ft | 600 | 66.7 | 55.7 |
A 12 × 12 room is 144 square feet.
Who it is for
A sq ft calculator for trades that price by area
Flooring and tile installers
Measure the rooms, add waste and know how much to order.
Painters and cleaners
Price a job by the square foot from the room sizes.
Homeowners
Work out a room before you buy flooring, sod or paint.
How do I calculate square footage?
Multiply the length by the width, both in feet. A room 12 feet by 10 feet is 120 square feet. If you measured in inches, divide each by 12 first, or type feet and inches here and it is done for you.
How many square feet is a 12x12 room?
A 12 by 12 foot room is 144 square feet. A 10x10 room is 100 square feet, a 12x15 room is 180 and a 20x20 room is 400.
How do I measure a room that is not a rectangle?
Split it into rectangles, measure each one and add them together. An L-shaped room is two rectangles. Use a triangle for an angled corner and a circle for a round area, then add a row for each.
How much extra flooring should I add for waste?
A common rule of thumb is 5 to 10 percent for straight layouts and more for diagonal or patterned ones. Check the instructions for your material: the right figure depends on the product and the room.
How do I convert square feet to square yards or square meters?
Divide square feet by 9 for square yards, and multiply square feet by 0.0929 for square meters. 180 square feet is 20 square yards, or about 16.7 square meters. The calculator shows all three.
How do I work out the square footage of a wall?
Multiply the wall's length by its height. A wall 12 feet long and 8 feet high is 96 square feet. Add a row for each wall, and take off windows and doors if you need the paintable area.
Is the square footage calculator free?
Yes, with no sign-up. Your measurements are kept in your browser on this device and are never sent to WeBoss.
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