Area Calculator
Calculate the area of rectangles, squares, circles and triangles with standard geometry formulas. — free, fast and private.
Your area will appear here.
Examples: rectangle 5 × 4 = 20. Circle with radius 5 → π × 25 ≈ 78.54. Triangle with base 6 and height 4 = 12.
How to use Area Calculator
- Choose a shape: rectangle, square, circle or triangle.
- Enter the measurements in the same unit.
- Click Calculate Area.
- The result is in square units (for example cm² or m²).
Note: this tool runs in your browser. Nothing is uploaded.
Frequently Asked Questions
What is the formula for the area of a circle?
Area = π × radius². For a radius of 5, that is π × 25 ≈ 78.54 square units.
What units is the answer in?
Square units of whatever unit you entered — if you enter metres, the answer is in square metres (m²).
How do I find the area of a triangle?
Area = ½ × base × height. Use the vertical height, not the slanted side.
Is my data uploaded anywhere?
No. All calculations run in your browser and your numbers are never sent to a server.