Area Calculator
Calculate the area and perimeter of rectangles, triangles, circles, trapezoids, parallelograms, ellipses, and more. Works in feet, meters, inches, yards, centimeters, or millimeters.
Learn More About Area Calculator
What this area calculator measures
This calculator helps you find the area and perimeter of common two-dimensional shapes like rectangles, circles, triangles, trapezoids, and ellipses. It is useful for geometry homework, home projects, flooring estimates, and layout planning.
Because it supports multiple shapes and unit systems, you can switch between practical and classroom use cases without looking up a new formula each time.
Example area calculation
If you need to cover a rectangular patio that is 12 feet by 16 feet, the area is 192 square feet. If you also need trim or edging, the perimeter becomes important too, because it tells you the total distance around the outside.
For circles, triangles, and other shapes, the same idea applies, but the formulas change. The calculator handles those differences for you.
Area vs perimeter
Area tells you how much surface is inside the shape. Perimeter tells you the total length around the boundary. They answer different questions, so it helps to know which one your project actually needs.
For example, paint, sod, and flooring usually depend on area, while fencing, trim, and borders depend on perimeter.