Calculate area of any shape — circle, rectangle, triangle, square, trapezoid and more.
Area is the measurement of the 2-dimensional space enclosed within a shape. It is expressed in square units — square meters (m²), square feet (ft²), square centimeters (cm²), acres, or hectares. Our area calculator online quickly computes the area of any common geometric shape including circles, rectangles, triangles, trapezoids, and more.
Area calculations are essential in everyday life. When buying flooring or carpet, you need the floor area to know how much material to purchase. When painting walls, knowing the total surface area helps estimate paint needed. In gardening and landscaping, area helps calculate fertilizer, seeds, or sod required. In construction, floor plan area determines material costs and property valuation.
Different regions of the world use different traditional land measurement units alongside the standard metric and imperial units. Common examples include the Acre (4,047 sq meters, widely used in the US and UK), Hectare (10,000 sq meters, the standard metric unit for land worldwide), and various local units used in South Asia, such as Bigha, Gunta, and Marla, which vary in exact size by region. Our calculator works with standard metric and imperial units — for regional units, check the local conversion factor for your specific area, since these can vary significantly by state or district.
For irregular shapes, divide the area into regular shapes (rectangles, triangles), calculate each separately, and add them together. Alternatively, use the coordinate geometry method — if you have the GPS coordinates of all corners, the Shoelace formula calculates the exact area. For land surveying purposes, always consult a licensed surveyor for legal documentation.
Area calculations are only as accurate as the shape assumption behind them. A room that looks rectangular often has small irregularities — a bump-out for a closet, an angled wall, or a curved alcove — that a simple length-times-width calculation will not capture. For most home projects like flooring, paint, or carpet estimates, breaking an irregular room into two or three simple rectangles and adding their areas together gives a far more accurate total than trying to force one shape to fit.
Unit choice matters just as much as shape choice. Flooring and paint are usually sold by square footage in the US and by square meters in most of the rest of the world, so mixing up units at the purchasing stage is a common and costly mistake. Always double-check the unit that a supplier's pricing is based on before ordering materials calculated from this tool.
Professionals typically add 5 to 10 percent extra to a calculated area when ordering flooring, tile, or turf, to account for cuts, waste, and pattern matching. For diagonal tile layouts or rooms with many corners, that buffer can reasonably go up to 15 percent. Calculating the exact area is the first step — planning for real-world waste is what prevents a second trip to the store.
A rectangle's area is length times width. A triangle's area is half of base times height. A circle's area is pi times the radius squared. A trapezoid's area is the average of the two parallel sides multiplied by the height. Knowing which formula applies to a given shape — and correctly identifying the base and height, which are not always the two most obvious sides of a shape — is the most common source of manual calculation errors that this tool eliminates.
Area is the amount of 2D space inside a shape, measured in square units like square meters (m²), square feet (ft²), or square centimeters (cm²).
Area of a circle = π × r², where r is the radius. For example, a circle with radius 5 cm has area = 3.14159 × 25 = 78.54 cm².
Area of a triangle = (base × height) / 2. For a triangle with base 10 and height 6, area = (10 × 6) / 2 = 30 square units.
Area is the space inside a shape (2D). Perimeter is the total length of the boundary around the shape (1D).
