Online calculators

Our site contains more than 100 free online calculators on math, geometry and physics.

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Calculating the area of a circle online

Our online calculator allows you calculate the area of a circle in two ways: through the radius or the diameter of the circle. To find the area of a circle, select the appropriate method, enter the length of the radius or diameter, and then click “To calculate”, the calculator will give the answer and the solution step by step!

Enter the data for calculating the area
Select the method of calculating the area:
The formula through the radius:
r =
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