Calculate the area of common geometric shapes including circles, squares, rectangles, triangles, trapezoids, and ellipses. Get step-by-step formulas, perimeter values, and solutions for school math and construction projects.
Area is the size of a two-dimensional surface. Our free online Area Calculator simplifies calculating surface areas for common geometric shapes. Simply select the shape (rectangle, square, circle, triangle, trapezoid, ellipse, or sector) and enter the required dimensions to calculate the exact area.
Different shapes require specific area formulas: Rectangle (L × W), Circle (πr^2), Triangle (1/2 × B × H), and Trapezoid (1/2 × (a + b) × H). The tool automatically performs conversions to provide accurate results.
The area of a circle is calculated using the formula: Area = pi * r^2, where r is the radius of the circle and pi is approximately 3.14159.
Area measures the space inside a two-dimensional shape, expressed in square units. Perimeter measures the total distance around the outside edge of the shape, expressed in linear units.
To find the area of a trapezoid, use the formula: Area = 1/2 * (a + b) * h, where 'a' and 'b' are the lengths of the parallel bases and 'h' is the perpendicular height.
To convert square inches to square feet, divide the area value by 144 (since 12 inches * 12 inches = 144 square inches in one square foot).