Square Footage Calculator
From tape measure to total area. Enter feet and inches, split an unusual room,
and add your spaces together.
Make every square foot count.
Measure your space
Read your tape in feet and inches, or choose metric. Measure the actual floor you want to cover.
Add it up
Choose a shape, add a closet or subtract a cutout. Combine your rooms for one net area.
Plan your purchase
Bring your area into the flooring calculator to add waste, round to boxes and estimate costs.
Square Footage Calculator With Feet and Inches
Most rooms don't measure out in neat whole feet. The calculator above takes feet and inches together — enter 12 in the feet field and 6 in the inches field, and it works with 12.5 decimal feet, not 12.6. A room 12 ft 6 in long and 10 ft wide is 12.5 × 10 = 125 square feet.
You can mix units inside one project. Measure one room in feet and inches, another in meters, and the calculator converts both before it totals them. Fractional inches work too: type 6 1/2 or 6½ in the inches field.
Converting Inches to Square Feet
Divide inches by 12 to get decimal feet, then multiply length by width:
square feet = length (ft) × width (ft)
Worked examples:
- 8 ft 6 in × 10 ft → 8.5 × 10 = 85 sq ft
- 11 ft 3 in × 9 ft 6 in → 11.25 × 9.5 ≈ 106.88 sq ft
- 144 in × 120 in → 12 × 10 = 120 sq ft
If you measure everything in inches, divide the result by 144 to get square feet (144 square inches = 1 square foot).
For length addition, subtraction and conversions, use our feet and inches calculator .
After measuring your rooms, use the flooring calculator to estimate material cost, waste, and the number of boxes to buy.
What is square footage?
Square footage measures area in square feet. One square foot is a square with sides one foot long. For a rectangular room, multiply length by width after converting both measurements to feet.
A room 12 feet 6 inches long and 10 feet wide is 12.5 × 10 = 125 square feet. Keep feet and inches separate above and the calculator handles the conversion.
Convert square meters to square feet
A foot is exactly 0.3048 meters. Area has two dimensions, so square that conversion: one square foot equals 0.09290304 square meters. To convert square meters to square feet, multiply by approximately 10.7639. To go the other way, multiply square feet by 0.09290304.
Square meters = square feet × 0.09290304
For example, a room measuring 3 meters by 4 meters has an area of 12 square meters, or about 129.17 square feet. Choose Meters above and enter the two lengths; the result includes both units. If you already know the area in square meters, use the area conversion formula rather than entering it as a length. Keep full precision while calculating and round only the final displayed result.
Read the step-by-step measuring guideCommon room sizes
| Room dimensions | Area |
|---|---|
| 8 × 10 ft | 80 sq ft |
| 10 × 10 ft | 100 sq ft |
| 10 × 12 ft | 120 sq ft |
| 12 × 12 ft | 144 sq ft |
| 12 × 14 ft | 168 sq ft |
| 14 × 16 ft | 224 sq ft |
| 15 × 15 ft | 225 sq ft |
| 20 × 20 ft | 400 sq ft |
Examples use exact rectangular dimensions.
Why do U.S. rooms use square feet?
Square feet belong to the U.S. customary measurement system. The United States uses both customary and metric units; its shift to metric has largely been voluntary, as NIST explains. Existing building plans, tape measures and supplier conventions help keep feet familiar in home projects. Neither unit makes an area more accurate. Use the unit on your material packaging when comparing coverage and prices, and convert the entire calculation consistently.
These room sizes are examples, not minimum bedroom requirements or averages. Measure your own space rather than selecting the nearest row. An 8 × 10 ft room is 80 square feet; a 15 × 15 ft room is 225 square feet. Closets, alcoves and missing corners can change the usable area even when the main dimensions match a table entry.
Common uses for a square footage calculator
A useful estimate starts by choosing the surface you actually want to cover. Floor area helps with flooring, a ceiling has its own area, and painted walls need their lengths and heights. Record the measured area before adding any allowance for cuts or extra coats, so you can explain each change to your shopping list.
Flooring: separate waste from whole-box rounding
For a straightforward plank layout, your supplier may recommend 5–10% extra for cuts and fitting. That is a starting estimate, not a rule for every product. Diagonal layouts, many corners and the ability to reuse offcuts can change the allowance. Confirm the installation instructions before ordering, then use the flooring calculator to compare the chosen waste rate with the exact coverage printed on each box.
Consider 168 square feet of measured floor with 10% waste: you need 184.8 square feet of material. At 22 square feet per box, eight boxes would cover only 176 square feet, so buy nine boxes. Their purchased coverage is 198 square feet. The additional 13.2 square feet comes from rounding to whole boxes, beyond the waste you already allowed. At $3 per square foot, those boxes cost $594 before other charges.
Add together rooms using the same product before rounding to boxes. Calculate different products separately. Extra spare boxes for future repairs are a separate choice, and installer labor may be charged against net floor area instead of purchased coverage. Ask for itemized pricing when comparing quotes; a material total alone does not include tax, delivery, preparation or installation.
Painting: calculate wall area, not floor area
Multiply each wall’s length by its height and add the wall areas. Subtract doors and windows that will not be painted, using their actual measurements. For a rectangular 12 × 10 ft room with 8 ft walls, the wall area before deductions is (12 + 10 + 12 + 10) × 8 = 352 square feet. The 120-square-foot floor does not tell you how much paint the walls need.
Multiply the paintable area by the number of coats, then divide by the coverage per gallon on the paint label. Check whether that coverage describes one coat. Surface texture, porosity and application method affect the result; primer and ceilings may require separate quantities. A paint manufacturer’s calculator can help turn your measured wall area into an order.
Tile: allow for the actual cutting pattern
Measure the tiled floor, wall or backsplash and keep it separate from areas that stay uncovered. If your installer recommends a 15% cutting allowance, a 100-square-foot surface needs 115 square feet before rounding to packs. Fifteen percent is an example, not a universal requirement: tile size, pattern, breakage and narrow cuts can change how much extra is needed.
Use the package’s stated coverage for the selected tile. An area estimate cannot decide the best tile layout, grout spacing or whether an offcut fits another edge. Confirm the pattern and allowance with your installer, and check batch availability and unopened-pack returns before placing the order.
A few things worth getting right.
How do I measure an L-shaped room?
Measure the full outer rectangle and the rectangular corner that is missing. Subtract the missing area. You can also split the L into two non-overlapping rectangles and add them. Never count the same area twice.
Is 12 feet 6 inches the same as 12.6 feet?
No. Six inches is half a foot, so 12 ft 6 in is 12.5 ft. A decimal such as 12.6 ft means 12 feet plus 0.6 of a foot, or 7.2 inches.
Can I add more than one room?
Yes. Add up to 20 rooms. Give each an optional name, choose its shape and enter its dimensions. The total includes all rooms, so leave no unfinished room in the project.
Do I add waste when measuring?
Measure net area first. Add a separate waste allowance in the flooring calculator. Waste varies with product, layout and installation method; ask your supplier or installer what is appropriate.
Is square footage the same as linear feet?
No. Linear feet measure length. Square feet measure area. To calculate area from a material’s length, you also need its width in the same units.
Can I use this for a property listing?
This tool calculates geometric area from the dimensions you enter. It does not determine which spaces count under local appraisal, building or listing rules. Use the applicable measurement standard for that purpose.
How do I calculate square feet from inches?
Convert inches to feet first by dividing by 12, then multiply length by width. 144 inches is 12 feet. So a surface 144 in × 120 in is 12 ft × 10 ft = 120 square feet. If you measured both sides in inches, multiply them and divide by 144 instead.
What is 12x12 in square feet?
144 square feet (12 × 12). A 10x10 room is 100 square feet, and a 10x12 room is 120 square feet. These are exact rectangular dimensions. Include closets or alcoves you will cover; subtract only excluded areas already included in your rectangle.
How do I convert square meters to square feet?
Multiply square meters by about 10.7639. A room 3 meters by 4 meters is 12 square meters, or about 129.17 square feet. Choose Meters in the calculator, or use that conversion when you already know the area in square meters.
Is the square footage calculator free?
Yes. It is free, needs no account, and keeps your measurements in the current browser tab until you reset or leave.