Calculators & Converters
Area Calculator
The Area Calculator works out the area of several common shapes, including rectangles, circles, triangles and trapezoids, based on the dimensions you provide, such as length and width, radius, base and height. It's useful for students tackling geometry homework, DIYers estimating materials like flooring or paint, and gardeners planning out a plot of land.
Every calculation happens instantly in your browser as you type your dimensions, using the standard geometric formula for whichever shape you select, with no server processing involved. That lets you quickly switch between shapes or tweak a measurement and see the area update right away.
How to Use the Area Calculator
- Open the Area Calculator tool.
- Select the shape you want to calculate, such as rectangle, circle, triangle or trapezoid.
- Enter the required dimensions for that shape, like length and width or radius.
- View the calculated area, updated instantly as you adjust any dimension.
Frequently Asked Questions
What formulas does the Area Calculator use?
It uses the standard geometric formulas for each shape, for example length x width for a rectangle, pi x radius squared for a circle, and half of base x height for a triangle.
What units does the result use?
The area is shown in square units matching whatever unit you entered your dimensions in, so keep your measurements in a consistent unit for an accurate result.
Can I calculate the area of irregular shapes?
This tool covers standard shapes only; for an irregular shape you would typically need to break it into simpler shapes and add the areas together.