Area Calculator

Calculate the area of shapes easily. Rectangle, circle, triangle, trapezoid, ellipse and more. Free online tool.

Select Shape

Length

Width

How It Works

Select the shape you want to calculate (circle, rectangle, triangle, trapezoid, or parallelogram).
Enter the required dimensions for the selected shape.
The area is calculated instantly as you type.
Copy the result with one click.

Circle:          A = π × r²
Rectangle:       A = l × w
Triangle:        A = ½ × b × h
Trapezoid:       A = ½ × (a + b) × h
Parallelogram:   A = b × h

Input: Rectangle: length = 8, width = 5

Result: Area = 40

Circle, rectangle, square, triangle, trapezoid, parallelogram, rhombus, and ellipse.

Any unit you like — just enter the numbers. The result is in the square of whatever unit you use.

No. All calculations run entirely in your browser. No data is sent to or stored on our servers.

A = π × r², where r is the radius of the circle.