Math calculator
Area Calculator
Calculate area of common shapes.
About the area calculator
The area calculator finds the area of common shapes: circle, triangle, rectangle, trapezoid, and ellipse.
How to use this calculator
- 1
Choose shape
Select the shape you want to calculate.
- 2
Enter dimensions
Enter the required dimensions for your shape.
- 3
View results
See the area.
How the calculation works
Circle: πr². Triangle: ½bh. Rectangle: lw. Trapezoid: ½(a+b)h. Ellipse: πab.
Example: Circle r=5: area ≈ 78.54.
When to use a calculator vs. mental math
Simple operations like percentages and proportions are great for mental math. Complex problems — quadratic equations, standard deviation, and base conversions — benefit from calculator precision. Always estimate the answer first to catch input errors, and verify results with a second method when possible.
Important limitations
This tool provides a mathematical estimate based only on the values entered. It does not account for regulations, taxes, lender fees, market conditions, or individual circumstances. Results are for planning purposes only — consult a qualified professional for regulated, medical, financial, or construction decisions.
Frequently asked questions about area calculator
How accurate is the area calculator?+
The calculation follows the displayed formula and retains full numeric precision before formatting the result.
Can I use the result professionally?+
Use it as a planning estimate. Confirm regulated, medical, financial, or construction decisions with a qualified professional.