# Area of a Circle Calculator

Calculate the area of a circle based on its radius (r) or diameter (d) in selected units, and see the detailed step-by-step calculation process.

Area = π * r²

Result:

## How to use this calculator?

- Enter the
**Circle Radius (r)**or**Circle Diameter (d)**in the selected unit. - See the calculated
**Area of a Circle**and if needed, change its unit. - See the detailed, step-by-step
**Calculation**process.

## How to calculate Area of a Circle?

Multiply PI (approximately 3.14) by the squared Circle Radius.

Area of a Circle = π * r²

- π - Pi (~3,14)
- r - Circle Radius

If only the Diameter is given, divide it by 2 to obtain the Radius.

Radius = Diameter / 2

**Example 1:**Calculate the area of a circle with a radius of 8 cm.

Area = π * r²

Area = π * (8 cm)²

Area ≈ 3.14 * 64 cm²

Area ≈ 200.96 cm²

**Example 2:**Calculate the area of a circle with a diameter of 14 cm.

Radius = d / 2

Radius = 14 cm / 2

Radius = 7 cm

Area = π * r²

Area = π * (7 cm)²

Area ≈ 3.14 * 49 cm²

Area ≈ 153.86 cm²