Area of Circle Calculator

The Circle Area Calculator is a handy tool that determines the area enclosed by a circle, based on its radius or diameter. The area of a circle represents the total space within its boundary. This calculator is applicable in various scenarios, from simple home projects to complex scientific and engineering calculations.

This calculator is beneficial for:

• Home Improvement Projects: Calculating the area of circular spaces for flooring or painting.
• Gardening: Determining the area of circular garden beds.
• Engineering and Design: Calculating the surface area of circular components.
• Educational Purposes: Assisting in understanding the concept and calculation of circle area.

The area of a circle can be calculated using either of the following formulas:

A = π × r²

Or,

A = π × (d/2)²

Where:

• A = Area
• π (pi) ≈ 3.14159
• r = Radius of the circle
• d = Diameter of the circle (d = 2r)

For example, to calculate the area of a circle with a radius of 6 cm:

A = π × (6 cm)²

A = π × 36 cm²

A ≈ 3.14159 × 36 cm²

A ≈ 113.1 cm²

Another example, with a diameter of 10 inches:

A = π × (10 in / 2)²

A = π × (5 in)²

A = π × 25 in²

A ≈ 3.14159 × 25 in²

A ≈ 78.54 in²

1. What units can I use for the radius or diameter?

   You can use any unit of length, such as centimeters, meters, inches, or feet. The area will be in square units of the same unit of length.

2. Can I use this calculator to find the radius or diameter if I know the area?

   Yes, you can rearrange the formulas. To find the radius, use r = √(A / π). To find the diameter, use d = 2 × √(A / π).

3. How accurate is the result?

   The accuracy depends on the precision of the value used for π (pi). Using a more precise value for π will provide a more accurate result.

4. What is the relationship between the radius and area of a circle?

   The area of a circle is directly proportional to the square of its radius. This means if you double the radius, the area becomes four times larger.

5. Can I use this calculator for a semi-circle or a sector of a circle?

   To find the area of a semi-circle, calculate the full circle area and divide by 2. For a sector, you'll need the central angle and use a proportion to find the area of that sector.