# Diameter of circle calculator

# Diameter of circle calculator

To calculate the diameter of a circle, you can use the following formula:

**diameter = 2 × radius**

where “diameter” is the distance across the circle passing through the center, and “radius” is the distance from the center of the circle to any point on its perimeter.

So, to find the diameter of a circle, you need to know the value of its radius. If you have the radius, simply multiply it by 2 to get the diameter.

Alternatively, if you have the circumference of the circle, you can use the following formula to find the diameter:

**diameter = circumference / π**

where “π” is the mathematical constant pi, which is approximately equal to 3.14159.

For example, if the radius of a circle is 5 cm, then its diameter is:

**diameter = 2 × 5 cm = 10 cm**

And if the circumference of a circle is 20 cm, then its diameter is:

**diameter = 20 cm / 3.14159 ≈ 6.366 cm**

### To find the diameter of a circle, you can follow these steps:

- Measure the radius of the circle: Use a ruler or measuring tape to find the distance from the center of the circle to any point on its perimeter. Make sure to measure in the same units (e.g. centimeters, inches) as you want the diameter to be in.
- Multiply the radius by 2: The diameter of a circle is always twice the length of its radius. So, once you have the radius measurement, multiply it by 2 to get the diameter.

Alternatively, if you know the circumference of the circle but not the radius, you can use the formula:

**diameter = circumference / π**

where π is the mathematical constant pi (approximately equal to 3.14159). To use this formula, simply divide the circumference by pi to get the diameter.

For example, let’s say you have a circle with a radius of 7 centimeters. To find the diameter, you would:

**diameter = 2 × radius diameter = 2 × 7 cm diameter = 14 cm**

So the diameter of the circle is 14 centimeters.

Alternatively, if you have a circle with a circumference of 20 centimeters and you want to find the diameter, you would:

**diameter = circumference / π diameter = 20 cm / 3.14159 diameter ≈ 6.366 cm**

So the diameter of the circle is approximately 6.366 centimeters.