Add 10% extra: For waste, cuts, and mistakes when ordering materials
Measure twice: Accuracy saves money on materials
Complex rooms: Break into simple shapes, then add areas
Whether you are planning a renovation, buying flooring, or listing a property, accurate square footage measurements are essential. Our free Square Footage Calculator computes area for rooms, walls, and spaces of all shapes.
What Is Square Footage?
Square footage (sq ft) is a measurement of area expressed in square feet. One square foot is a square measuring 12 inches on each side. Square footage is used to measure:
Room size: Living spaces, bedrooms, kitchens
Property value: Price per square foot in real estate
Material needs: Flooring, paint, tile quantities
HVAC sizing: Heating and cooling capacity
Lot size: Land area measurements
How to Calculate Square Footage
Rectangular Spaces
Square Feet = Length × Width
For a 12 ft × 10 ft room: 12 × 10 = 120 sq ft
Measurement Tips
Measure in feet: Convert inches to feet (6 inches = 0.5 feet)
Measure at multiple points: Walls may not be perfectly square
Use the longest measurement: For materials, round up
Record carefully: Label length and width to avoid confusion
Always add 10-15% extra when ordering materials to account for waste, cuts, and mistakes
It is cheaper than a second trip to the store for more materials
For patterned materials (tile, wallpaper), add 15-20% extra for matching patterns
Round up to whole boxes/packages - you cannot buy partial boxes of tile
Keep extra material for future repairs (especially flooring and tile)
Square Footage Around the World
While square footage is the standard unit in the United States and Canada, other countries primarily use square metres. Understanding international measurement conventions helps when comparing properties, estimating material costs from foreign suppliers, or relocating abroad. The table below outlines how each major region handles area measurement in real estate and home improvement contexts.
Square Footage Standards by Country
Country / Region
Primary Unit
Typical Home Size
Real Estate Standard
Key Conversion
USA
Square feet (sq ft)
~2,000 sq ft (186 m²)
Square feet listed on all MLS listings; legally required in many states
1 sq ft = 0.0929 m²
United Kingdom
Square feet & square metres
~925 sq ft (86 m²)
Both units used; newer developments often list in m²; Rightmove shows both
1 m² = 10.764 sq ft
Canada
Square feet (common in real estate)
~1,640 sq ft (152 m²)
MLS listings typically use sq ft despite metric being the official system
1 sq ft = 0.0929 m²
Australia
Square metres (m²)
~186 m² (~2,002 sq ft)
Domain and realestate.com.au list in m²; land areas often in square metres or hectares
1 m² = 10.764 sq ft
India
Square feet (urban); sq yards
~1,000–1,200 sq ft (93–111 m²)
Major portals (MagicBricks, 99acres) use sq ft; land plots measured in sq yards or cents in southern states
1 sq yard = 9 sq ft
Quick Conversion Tip: To convert square feet to square metres, divide by 10.764. To convert square metres to square feet, multiply by 10.764. Our calculator works in square feet but the result can also be reported in other units via the conversion tool.
Frequently Asked Questions
Break it into rectangles and triangles, calculate each area, then add them together. For L-shaped rooms, divide into two rectangles. For rooms with angled walls, use the triangle formula for the angled section. Measure carefully at the longest points of each section. It is better to overestimate slightly than to run short on materials.
Divide inches by 12 to convert to feet. For example: 6 inches = 0.5 feet. A room 10 feet 6 inches wide = 10.5 feet. For more precision: 3 inches = 0.25 feet, 9 inches = 0.75 feet. Write down measurements in feet with decimals before calculating to avoid errors.
Calculate square footage, then add 10-15% for waste. A 200 sq ft room needs 220-230 sq ft of flooring material. For diagonal installation or complex patterns, add 15%. For standard straight installation, 10% is usually sufficient. Always round up to the next full box or package - you cannot buy partial boxes, and extra material is useful for future repairs.
Measure each wall (height × width), add them together, then subtract window and door areas. For a 10×12 room with 8 ft ceilings: Two walls: 10 ft × 8 ft = 80 sq ft each (160 total). Two walls: 12 ft × 8 ft = 96 sq ft each (192 total). Total wall area: 352 sq ft. Subtract one standard door (21 sq ft) and one window (12 sq ft): 352 - 33 = 319 sq ft to paint.
Linear feet measures length only (12 ft long). Square feet measures area (12 ft × 10 ft = 120 sq ft). You use linear feet for trim, baseboards, and fencing. You use square feet for flooring, paint, and sod. A 12 ft length of 6-inch-wide flooring = 6 sq ft (12 × 0.5 = 6).
Measure each stair is tread (depth) and riser (height). Standard tread = 11 inches, riser = 7 inches. Total per stair = 18 inches (1.5 feet). Multiply by stair width (usually 36 inches = 3 feet). Area per stair = 1.5 ft × 3 ft = 4.5 sq ft. Multiply by number of stairs. Add 20% extra for wrapping around edges and pattern matching.
Multiply square meters by 10.764 to get square feet. Example: 50 sq m × 10.764 = 538.2 sq ft. To go from sq ft to sq m, divide by 10.764. This conversion is useful when looking at international property listings or working with metric-based products.
One acre = 43,560 square feet. A standard residential lot is often 1/4 acre (10,890 sq ft) to 1/2 acre (21,780 sq ft). One square mile = 640 acres. An acre is approximately 208.7 feet × 208.7 feet, or about 90% of a football field (excluding end zones).
Typically yes for total home square footage - closets are counted as part of the room they serve. For flooring, measure closets separately if using different materials. Walk-in closets count fully toward sq ft. Small reach-in closets may or may not be counted depending on local real estate practices. When in doubt, measure them and include them.
Break it into triangles and rectangles. For a bay window or angled wall: Measure the rectangular portion normally. For the angled section, measure the base (where it meets the wall) and the height (how far it extends into the room). Use the triangle formula: (base × height) ÷ 2. Add this to the rectangle area.
Heated/cooled living space: bedrooms, living areas, kitchens, bathrooms, hallways. Usually excludes: garages, porches, unfinished basements, attics. Finished basements may be included but noted separately. ANSI standards require measuring exterior dimensions for above-grade space. Different states/counties may have slight variations in what is included.
Square footage × height = cubic feet. A 120 sq ft room with 8 ft ceiling = 960 cubic feet. This is useful for: HVAC sizing (air volume), painting (for vaulted ceilings), mulch or gravel depth (add thickness to sq ft calculation). For storage capacity or air handling, cubic footage matters more than square footage.
Calculate floor area normally - tile coverage accounts for standard grout spacing. Add 10-15% for cuts and waste (more if diagonal pattern). For a 100 sq ft bathroom: order 115 sq ft of tile. Round up to full boxes. Consider tile size: larger tiles have less grout but more waste on cuts. Small mosaic tiles on mesh sheets are calculated by sheet coverage.
Within 1/4 inch for most projects. Measure twice, cut once! Round up when ordering materials. For professional flooring installation, some contractors measure within 1/8 inch. If walls are visibly out of square, take multiple measurements and use the largest. For real estate listings, accuracy is legally important - measure carefully or hire a professional.
Divide total price by square footage. A $300,000 home at 2,000 sq ft = $150/sq ft. For flooring: $500 total for 200 sq ft = $2.50/sq ft installed. Price per sq ft allows comparison between different sized properties or products. In real estate, compare similar properties - condos vs single-family homes have different typical $/sq ft values.
Methodology: This calculator uses standard geometric formulas to calculate area for various shapes. All calculations assume flat, two-dimensional surfaces.
This calculator is provided for educational and planning purposes. Always verify measurements before purchasing materials.
Calculate Your Square Footage
Measure any space with precision. Get accurate area calculations for flooring, paint, real estate, and more.
