Area Calculator
Calculate the area of rectangles, circles, triangles, and other common shapes.
What Is the Area Calculator?
The area calculator computes the area of common 2D shapes including rectangles, circles, triangles, trapezoids, and ellipses. Simply select a shape, enter the required dimensions, and get an instant result with the formula shown.
Formula
How to Use
Select the shape you want to calculate the area for. Enter the required measurements (all values must be positive). Click Calculate Area to see the result.
Example Calculation
For a circle with radius 7: Area = π × 7² = π × 49 ≈ 153.938 square units.
Understanding Area
Area calculation is fundamental in geometry, architecture, landscaping, interior design, and many everyday tasks. Whether you are determining how much paint to buy, calculating floor space, or working on a geometry assignment, knowing how to compute areas is essential.
Each shape has its own formula derived from geometric principles. The rectangle formula (length × width) is the simplest. The circle formula (πr²) relates to the ratio of a circle's area to its radius. The triangle formula (½ × base × height) comes from the fact that a triangle is half a rectangle.
Our calculator supports five common shapes and displays the formula with substituted values so you can see exactly how the result was computed. This makes it both a calculation tool and a learning aid.
Frequently Asked Questions
What units does this calculator use?
The calculator works with any consistent unit. If you enter measurements in centimeters, the result is in square centimeters. If you enter meters, the result is in square meters.
How do I calculate the area of an irregular shape?
Break the irregular shape into simpler shapes (rectangles, triangles, etc.), calculate each area separately, and add them together.
What is the difference between area and perimeter?
Area measures the surface enclosed by a shape (in square units). Perimeter measures the distance around the outside edge (in linear units).