Area Calculator
Calculate area for common shapes: rectangle, square, circle (radius), and triangle (base × height / 2).
How it works
- 1
Enter your values in the fields.
- 2
Results update automatically as you type.
- 3
Use Reset to clear and try another scenario.
Why use this calculator
- Multiple shapes
- Instant area
- Simple dimensions
- Handy for DIY and school
Geometry without friction
Pick a shape, enter dimensions, and get area in square units matching your inputs.
Circle input
For circles, enter the radius in the first dimension field.
Frequently asked questions
Which field is radius?
For circle mode, dimension A is the radius.
Triangle needs height?
Yes — base and height for the triangle mode on this page.
Unit conversion?
Convert units before entering values; output uses the same unit squared.