Square Footage Calculator
Work out the square feet of any room. Enter length and width in feet and inches or in meters; the area appears in sq ft and m² as you type, with the math shown.
Reference table
Square Footage of Common Room Sizes
Length × width for room sizes people often ask about.
| Room size | Square feet | Square meters | Good to know |
|---|---|---|---|
| 7 × 10 ft | 70 | 6.5 | IRC minimum for a habitable room; no side under 7 ft |
| 10 × 10 ft | 100 | 9.29 | Small bedroom, nursery or home office |
| 10 × 11 ft | 110 | 10.22 | Kids' bedroom or guest room |
| 10 × 12 ft | 120 | 11.15 | Common secondary bedroom size |
| 11 × 11 ft | 121 | 11.24 | Square bedroom or study |
| 10 × 14 ft | 140 | 13.01 | Long bedroom, office or dining room |
| 12 × 12 ft | 144 | 13.38 | Queen bed (60 × 80 in) with 3 ft 6 in each side |
| 12 × 14 ft | 168 | 15.61 | Roomy secondary or small primary bedroom |
| 14 × 14 ft | 196 | 18.21 | Primary bedroom or small living room |
| 14 × 16 ft | 224 | 20.81 | Primary bedroom with seating, or living room |
| 16 × 16 ft | 256 | 23.78 | Living room or family room |
| 20 × 20 ft | 400 | 37.16 | Large living room or open kitchen-dining |
Uses are typical, not rules. The 70 sq ft minimum (kitchens exempt) is section R304 of the International Residential Code; local codes can differ, so check with your building department.
Area to room size
How Big Is a 100, 150 or 300 Square Foot Room?
Working backwards: the side of a square room with that area, and a rectangle with exactly that area.
| Area | Square meters | Square room, each side | Example rectangle |
|---|---|---|---|
| 100 sq ft | 9.29 | 10 ft | 8 ft × 12 ft 6 in |
| 120 sq ft | 11.15 | 10 ft 11 in | 10 × 12 ft |
| 150 sq ft | 13.94 | 12 ft 3 in | 10 × 15 ft |
| 200 sq ft | 18.58 | 14 ft 2 in | 12 ft 6 in × 16 ft |
| 250 sq ft | 23.23 | 15 ft 10 in | 12 ft 6 in × 20 ft |
| 300 sq ft | 27.87 | 17 ft 4 in | 15 × 20 ft |
| 400 sq ft | 37.16 | 20 ft | 16 × 25 ft |
| 500 sq ft | 46.45 | 22 ft 4 in | 20 × 25 ft |
Square sides are rounded to the nearest inch.
Room Measurements Made Clear
Start With the Space Inside the Walls
Measure the floor from wall to wall, then enter its length and width. The result shows the area in both square feet and square meters, with the multiplication underneath so you can check your measurements.
Calculate Room AreaSplit an L-Shaped Room Into Two Parts
Divide the floor into rectangles A and B without overlapping them. Enter each rectangle’s own length and width in the L-shape tab. The calculator shows the area of each part and adds them into one total.
Measure an L-Shaped RoomAdd Rooms, Closets and Alcoves
Use Several areas to combine up to 6 rectangles. Include every floor section you plan to cover, and count each space once. Add any allowance for cuts separately, following your flooring supplier’s advice.
Add Your AreasTwo Units, One Result to Copy
Enter feet and inches or switch to meters. Inches of 12 or more carry over, so 14 in counts as 1 ft 2 in. Your dimensions convert with the unit switch, and both area formats stay visible. Copy the result and working into a quote request.
Try It in MetersHow to Calculate Square Feet of a Room
To work out the square footage of a room you need a tape measure and a minute. In metric, measure in meters and the answer is in square meters.
- 1
Measure the length and width
Measure wall to wall at floor level in both directions. Measure twice; if the walls are slightly out of square, use the larger number. Keep the inches rather than rounding to the nearest foot.
- 2
Multiply length by width
Length × width = area. A 12 × 10 ft room is 120 sq ft; a 4 × 3 m room is 12 m². Turn inches into feet first by dividing by 12: 12 ft 6 in is 12.5 ft, so 12.5 × 10 = 125 sq ft.
- 3
Split odd shapes, then add
Cut an L-shaped room into two rectangles with one straight line, find each area, and add them. Treat a closet or bay the same way. The rectangles must not overlap.
What to Do With a Room’s Square Footage
Ordering flooring
Flooring, tile and carpet are priced by the square foot or square meter. Measure every area that gets the new floor, closets included, and add the extra your supplier recommends for cuts.
Sizing a whole floor plan
Add up every room to get a home’s floor area, or start from a target like 1,800 sq ft and let a floor plan generator divide it into rooms. Garages and porches are usually counted separately.
Furniture and layout
Square footage says how big a room is, not whether a sofa fits. Compare the length and width with furniture dimensions, leaving space for walkways and door swings.
FAQ
Room Square Footage Questions
To get the square footage of a room, measure the length and width in feet and multiply them: a room 12 ft long and 10 ft wide is 12 × 10 = 120 square feet. For inches, divide them by 12 and add them to the feet first: 10 ft 6 in is 10.5 ft.
Split the L into two rectangles with one straight line, measure each, and add the two areas: 14 × 10 ft (140 sq ft) plus 8 × 6 ft (48 sq ft) is 188 sq ft. Keep the rectangles from overlapping so the corner isn’t counted twice.
A 12 × 12 ft room is 144 square feet, or 13.38 m². A 10 × 10 room is 100 sq ft, 14 × 14 is 196 sq ft and 16 × 16 is 256 sq ft.
About 12 ft 3 in on each side if it is square, or 10 × 15 ft as a rectangle. That is 13.94 m², around the size of a comfortable bedroom.
Measure in meters and multiply: 4 m × 3 m = 12 m². Square feet × 0.09290304 gives square meters; square meters × about 10.764 gives square feet. Both follow from 1 ft = 0.3048 m exactly.
For flooring, include closets and every other area getting the new floor, and usually leave out the footprint of fixed cabinets or a tub. For a listing, ask which measuring standard your agent or appraiser uses.
It uses exact conversion factors and rounds to 2 decimal places, so the answer is as good as your measurements. Measure each wall twice at floor level.
Not directly; it works with rectangles and shapes made of them. A triangular corner is base × height ÷ 2. A rectangle around a curved bay overestimates its area; measure the shape separately and confirm material allowances with your supplier.