--- title: "Square Footage Calculator" type: "page" canonical_url: "https://simcalculo.com/en/square-footage-calculator/" markdown_url: "https://simcalculo.com/en/square-footage-calculator.md" date_published: "2026-10-19T23:46:05-03:00" date_modified: "2026-10-19T23:46:05-03:00" author: "" language: "en-US" category: "" summary: "How to use the square footage calculator Choose feet, inches, meters or centimeters. Enter the two dimensions of a rectangular space and the number of identical spaces. Add more areas to total several rooms or non-overlapping parts of a larger space. Up to 20 rows…" --- # Square Footage Calculator AREA AND MATERIALS ## Square Footage Calculator Calculate rectangular floor, wall or land areas. Add rooms, allow for waste and estimate material cost. ### Area measurements Measurement unitFeet (ft)Inches (in)Meters (m)Centimeters (cm) Use length × width for floors or height × width for walls. Enter decimal numbers, such as 12.5; commas group thousands. For 5 ft 6 in, enter 5.5 feet or 66 inches. Changing units converts valid dimensions and the unit price. + Add area Waste allowance (%)Optional. Enter 0 for area only.Price per ft² (USD)Applied to the material area including your waste allowance. Calculate areaClear ### Calculation result Total area**** Material with allowance**** Estimated material cost**** Area breakdownAreaDimensionsQuantityArea Material = area × (1 + allowance ÷ 100). Cost = material × unit price. Labor, delivery, tax and rounding to boxes or whole pieces are not included. Copy result ### How to calculate square footage Multiply length by width in feet. For example, 12 ft × 10 ft = 120 ft². Inches are converted to feet before displaying square footage. Metric measurements return square meters. For an L-shaped or irregular space, split it into non-overlapping rectangles and add each one as a separate area. Account for doors and windows separately; negative dimensions are not accepted. Calculations run in your browser. This calculator does not save entries in browser storage or send them to our server. ## How to use the square footage calculator Choose feet, inches, meters or centimeters. Enter the two dimensions of a rectangular space and the number of identical spaces. Add more areas to total several rooms or non-overlapping parts of a larger space. Up to 20 rows are supported, with a quantity of 1 to 100 for each row. For feet, use decimal feet rather than feet-and-inches notation. For example, 5 feet 6 inches is 5.5 feet or 66 inches. Use a decimal point in the English version; commas group thousands. Changing units converts valid entered dimensions and the price per area, so the estimated physical area and cost remain consistent apart from display rounding. ## Square footage formula Rectangle area = length × width. A 12-foot by 10-foot room covers 120 square feet. For three identical rooms, multiply by three to get 360 square feet. Use the same dimension twice for a square. For walls, use height × width. For L-shaped or irregular spaces, split the shape into rectangles that do not overlap, calculate each part and add the areas. This calculator does not directly calculate circles or triangles, subtract openings or certify legal floor area. Account for doors and windows separately. ## Feet, inches and square meters Feet and inches return square feet; meters and centimeters return square meters. There are 12 inches in a foot, so 144 square inches equal one square foot. For example, 144 inches × 120 inches = 120 square feet. The conversion uses the international foot: 1 foot is exactly 0.3048 meters, so 1 square foot is 0.09290304 square meters. This follows the [NIST definition of the international foot](https://www.nist.gov/pml/us-surveyfoot). It does not use the retired U.S. survey foot. ## Estimate material with a waste allowance Material area = measured area × (1 + waste percentage ÷ 100). If your floor is 120 square feet and you enter 10% waste, the allowance adds 12 square feet and the material estimate is 132 square feet. The calculator accepts 0–100%; zero calculates the measured area without extra material. The allowance is your choice, not a product recommendation. Layout, cutting pattern, damage and product instructions affect the amount required. The calculator returns an area, not a whole number of packages. Divide by the coverage per box and round up separately when ordering. ## Estimate the material cost Cost = material area including allowance × price per output area unit. For 132 square feet at USD 4.50 per square foot, the estimated material cost is USD 594.00. Leave the price blank to hide the cost estimate; a price of zero is allowed. The price is USD per square foot for feet or inches, and USD per square meter for metric inputs. Switching units converts the unit price, not the currency. Labor, tax, delivery and package rounding are not included. For deck boards, use our [Deck Material Calculator](https://simcalculo.com/en/deck-material-calculator/) for board counts and cutting assumptions. ## Precision, limits and privacy Dimensions must be positive and no more than 1,000,000 in the selected unit. Quantity must be a whole number from 1 to 100, and the optional unit price must be between 0 and 1,000,000. The calculator rejects a total physical area above one billion square meters or a cost above one trillion. Calculations use JavaScript numbers and results display up to six decimal places; currency displays two. Converted input values retain up to ten decimal places. Small rounding differences can occur after repeated conversions. Verify measurements and product requirements before purchasing materials. Calculations run in your browser. The calculator does not send entered names, dimensions or prices to our server, save them in browser storage or transfer them when switching languages. The [Portuguese area calculator](https://simcalculo.com/pt-br/calculadora-metros-quadrados/) uses the same calculation code, with localized units, labels and number formatting.