Calculate square footage from length and width in any unit. Convert between sq ft, sq m, sq yd, and acres. Includes cost estimator, room presets, and a common sizes reference table.
Square footage is the most common way to express area in the United States, used in real estate listings, flooring estimates, painting jobs, landscaping, and construction bids. Whether you are buying a home, pricing tile, estimating paint coverage, or sizing air conditioners, you need to know how many square feet you are working with.
This calculator converts dimensions in any unit — feet, inches, yards, meters, or centimeters — into square feet and every other common area unit (sq m, sq yd, acres, and sq in). It supports rectangular, triangular, and circular areas, and a quantity multiplier lets you calculate multiple identical rooms at once.
The built-in cost estimator turns area into money: enter a price per square foot (flooring, painting, rent) and see the total cost instantly. This is invaluable for contractors quoting jobs, homeowners comparing materials, and real estate investors assessing price per square foot.
Presets load common scenarios — bedrooms, offices, garages, and lots — so you can see realistic numbers immediately. A reference table of typical room sizes helps you sanity-check your measurements. Highlighted rows show which standard room is closest to your calculated area, giving instant context.
This calculator is useful when the real question is bigger than a single area formula. You may need to compare rectangular, triangular, and circular spaces, multiply the result across several identical rooms, or turn square footage directly into a cost estimate. By keeping those steps in one place, the tool becomes practical for renovation budgets, room planning, lot sizing, and quick checks when you need both the measurement and the financial impact.
Rectangle: area = length × width Triangle: area = ½ × base × height Circle: area = π × radius² Conversions: 1 ft² = 144 in² = 0.1111 yd² = 0.0929 m² 1 acre = 43,560 ft² Cost = area (ft²) × price per ft²
Result: 224 sq ft, 20.81 sq m, 24.89 sq yd, $1,792 total cost
A 14 × 16 ft room = 224 sq ft. Converting: 224 × 0.0929 = 20.81 sq m, 224 ÷ 9 = 24.89 sq yd. At $8/sq ft, total cost = 224 × 8 = $1,792.
Square footage is the product of two perpendicular linear measurements, both in feet. For a rectangular room measure the longest dimension (length) and the shortest (width), then multiply. Always measure at the floor—walls that bow or angle at the top do not affect floor area. Use a laser distance measurer for large spaces; aim for ±½ inch per dimension to keep area error under 1 sq ft in a 15-ft room. For accuracy, take two measurements per wall and average them.
Real spaces rarely match simple rectangles. An L-shaped room splits into two rectangles. A bay window or alcove adds a small rectangle or trapezoid. A semicircular sunroom adds A = ½πr² to the main room. For each sub-region, sketch a diagram, label dimensions, compute sub-areas, and sum the pieces. Subtract columns, built-in features, and closet bulkheads that will not receive flooring. This additive approach handles any floor plan that can be decomposed into standard shapes.
Real estate listings report livable (heated, finished) square footage, which excludes garages, unfinished basements, and outdoor areas. Appraisers measure the exterior perimeter for gross living area (GLA), then subtract wall thickness and unfinished zones. Measured room-by-room interior square footage is typically 3–5% less than the GLA figure in a listing. The national median US home price per square foot ranges from about $150 in the Midwest to over $400 in coastal metro areas—making accurate area measurement one of the most financially significant calculations in a real estate transaction.
Knowing area unlocks cost estimates for almost every home improvement project. At $8/sq ft for LVP flooring, a 224 sq ft room costs $1,792 in material. At 350 sq ft per gallon for paint, a 500 sq ft wall area needs 1.43 gallons. Hardwood installation runs $6–$12/sq ft in labor. For renovation budgeting, always compute the square footage first, then multiply by the per-sq-ft benchmark for your material and region.
Multiply length by width in the same unit. If using feet, the result is in square feet. For other units, convert first or use this calculator which handles conversions automatically.
43,560 square feet. An acre is roughly 208.7 ft × 208.7 ft.
Multiply by 0.0929. For example, 500 sq ft × 0.0929 = 46.45 sq m.
It depends on context. For US homes, the national median is around $150/sq ft. For flooring, $2–$15/sq ft depending on material. For commercial rent, $15–$80/sq ft/year.
Divide the area into regular shapes (rectangles, triangles, circles), calculate each separately, and add them up. Subtract any cutouts.
Linear feet measure a one-dimensional length. Square feet measure two-dimensional area. You need both length and width to get square feet.