1. What is Radius?

The radius of a circle is the distance from the center of the circle to any point on its circumference. It is exactly half of the diameter of the circle.

2. How Does the Calculator Work?

The calculator uses the simple radius formula:

Where:

• \( r \) — Radius of the circle
• \( d \) — Diameter of the circle

Explanation: The radius is always half the length of the diameter, making this calculation straightforward.

3. Importance of Radius Calculation

Details: Knowing the radius is essential for many circle calculations including area (\( \pi r^2 \)), circumference (\( 2\pi r \)), and for many engineering and design applications involving circular shapes.

4. Using the Calculator

Tips: Simply enter the diameter of your circle in any units (inches, cm, meters, etc.). The result will be in the same units.

5. Frequently Asked Questions (FAQ)

Q1: Is radius always half of diameter?
A: Yes, by definition, the radius is exactly half the length of the diameter in a perfect circle.

Q2: Can I calculate diameter from radius?
A: Yes, simply multiply the radius by 2 to get the diameter.

Q3: What units should I use?
A: You can use any units of length (mm, cm, inches, feet, meters). The result will be in the same units as your input.

Q4: Does this work for spheres too?
A: Yes, the relationship between radius and diameter is the same for spheres as it is for circles.

Q5: Why is radius important in circle calculations?
A: Most circle formulas (area, circumference) use radius rather than diameter, making it a fundamental measurement.