Area Calculator

Calculate the area of common shapes — rectangle, circle, triangle, trapezoid, and ellipse.

Select the shape to calculate the area for.

Length for rectangle/trapezoid, radius for circle, base for triangle, semi-major axis for ellipse.

Width for rectangle, height for triangle/trapezoid, semi-minor axis for ellipse. Not used for circle.

Second base for trapezoid. Leave 0 for other shapes.

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Area Formulas for Common Shapes

Rectangle: A = length × width. Circle: A = πr². Triangle: A = ½ × base × height. Trapezoid: A = ½ × (base₁ + base₂) × height. Ellipse: A = π × a × b (where a and b are semi-major and semi-minor axes). These formulas cover the most common shapes encountered in everyday calculations.

Understanding Area Units

Area is measured in square units — square feet (ft²), square meters (m²), acres, hectares, etc. When converting, remember that 1 m² = 10.764 ft², 1 acre = 43,560 ft², and 1 hectare = 10,000 m². Always ensure all dimensions are in the same unit before calculating.

Irregular Shapes

For irregular shapes, divide them into recognizable shapes, calculate each area separately, and sum them. Alternatively, use the grid method (counting squares) or calculus for complex curves. Many real-world areas (rooms, lots) can be broken into rectangles and triangles.

Practical Applications

Area calculations are essential for home improvement (paint, flooring, tiling), landscaping (sod, mulch), construction (roofing, concrete), real estate (lot size), agriculture (crop planning), and manufacturing (material estimation). Accurate area measurements save time and money.

Frequently Asked Questions