About This Calculator
This area calculator supports 10 common 2D shapes: rectangle, circle, sector, triangle, trapezoid, parallelogram, ellipse, regular polygon, annulus, and bordered rectangle. You can input measurements in cm, m, in, or ft. All inputs are internally converted to meters for consistent and accurate area calculations.
How to Use
- Select a shape from the icon list.
- Enter valid positive dimensions, and angles if required.
- Click "Calculate" to get the area result in the selected unit.
Frequently Asked Questions
Which shapes are supported?
Supported shapes include rectangle, circle, sector, triangle, trapezoid, parallelogram, ellipse, regular polygon, annulus, and bordered rectangle.
Can I use feet or inches as units?
Yes. You can enter values in cm, m, in, or ft. The calculator standardizes them to meters for internal computation.
What does "bordered rectangle" mean?
It refers to the area of the outer rectangle minus the inner hollow portion defined by a uniform border width.
Why is angle limited to 360° for sectors?
A full circle is 360°. Any angle beyond that is invalid for sector calculations and will be rejected.
What is the minimum number of sides for a regular polygon?
The polygon must have at least 3 sides. The calculator enforces this with input validation.