Calculate areas of circles, rectangles, triangles, and other geometric shapes instantly. Our free online area calculator supports multiple geometric figures with precise formulas and step-by-step solutions.
No registration required. Works on all devices. Perfect for students, teachers, engineers, and anyone needing quick geometric calculations.
Enter the radius of your circle in any units (cm, m, inches, etc.)
Enter radius to calculate
The area of a circle is calculated using the formula: π × radius². The radius is the distance from the center to any point on the circle.
Our area calculator makes geometric area computations simple and accurate:
Select the shape you want to calculate the area for from the dropdown menu
Enter the required dimensions (radius, length, width, base, height, etc.) in the input fields
Choose your preferred unit of measurement (cm, m, inches, feet, etc.)
Click calculate to get the area result with formula and step-by-step solution
Copy or share the results as needed
Calculate the area of your rectangular room measuring 12 feet by 15 feet to determine how much flooring or carpet you need. Input length = 12ft, width = 15ft, get area = 180 sq ft.
Find the area of a circular garden with a radius of 5 meters. Input radius = 5m, get area = 78.54 sq m to determine how much soil or grass seed you need.
Calculate the area of a triangular plot with base 20m and height 15m for land surveying. Input base = 20m, height = 15m, get area = 150 sq m.
Learn and practice geometric formulas, complete homework assignments, and understand area calculation methods with step-by-step solutions.
Quickly calculate room dimensions, material requirements, floor plans, and construction measurements on-site.
Determine property boundaries, plot sizes, agricultural field areas, and terrain measurements.
Calculate cross-sectional areas, surface areas, and geometric properties for technical drawings and designs.
Area is a measure of the amount of two-dimensional space inside a closed figure. It represents the surface covered by a shape and is expressed in square units (square meters, square feet, etc.).
Different geometric shapes require specific formulas for area calculation. For example, the area of a rectangle is length × width, while the area of a circle is π × radius². Triangles use (base × height) ÷ 2, and more complex shapes like trapezoids use (sum of parallel sides × height) ÷ 2.
When calculating area, ensure all measurements use the same unit. Converting between units is crucial for accuracy - multiply by conversion factors as needed (1 foot = 12 inches, 1 meter = 100 cm, etc.). Understanding these principles helps in real-world applications like construction, manufacturing, and scientific measurements.
Mixing different units of measurement
Always convert all measurements to the same unit before calculating area to avoid incorrect results.
Confusing diameter with radius in circle calculations
Remember that radius is half the diameter when using the formula π × r² for circles.
Using slant height instead of perpendicular height for triangles
Area of triangles requires the perpendicular height from the base to the vertex, not the side length.
Forgetting to square the units in the final answer
Area is always expressed in square units (sq ft, sq m, sq cm) - don't forget to include the squared symbol.
Yes, our area calculator is completely free to use with no hidden charges, registration requirements, or premium features. All calculations happen locally in your browser with no data collected.
Currently our calculator supports standard geometric shapes. For irregular polygons, you can use the coordinates option by entering the x,y coordinates of each vertex to calculate the enclosed area.
Our calculator uses precise mathematical formulas and follows standard geometric principles. Results are accurate to several decimal places depending on your input precision.
Yes, our area calculator is fully responsive and works on smartphones, tablets, and desktop computers without any installation required.
For area calculations, you should only input positive numerical values representing physical dimensions. Fractions can be entered as decimals (e.g., 0.5 for 1/2).
There is no practical limit to the size you can calculate, though extremely large numbers may be displayed in scientific notation. The calculator handles both tiny and huge measurements accurately.