1. What is Circle Diameter?

The diameter of a circle is the longest distance from one point on the circle to another, passing through the center. It is exactly twice the length of the radius.

2. How Does the Calculator Work?

The calculator uses the diameter formula:

Where:

• \( d \) — Diameter (length units)
• \( r \) — Radius (length units)

Explanation: The diameter is simply twice the length of the radius, as all points on a circle are equidistant from the center.

3. Importance of Diameter Calculation

Details: Knowing the diameter is essential for calculating circumference, area, and other properties of circles in geometry, engineering, and physics.

4. Using the Calculator

Tips: Enter the radius in any length units (cm, m, inches, etc.). The result will be in the same units. Value must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between diameter and radius?
A: The radius is half the diameter - the distance from center to edge, while diameter spans the whole circle through the center.

Q2: Can I calculate radius from diameter?
A: Yes, simply divide the diameter by 2 to get the radius (\( r = d/2 \)).

Q3: What units should I use?
A: Any consistent length units can be used (meters, feet, etc.). The result will be in the same units as your input.

Q4: Does this work for spheres too?
A: Yes, the diameter of a sphere is also twice its radius, calculated the same way.

Q5: Why is diameter important in real-world applications?
A: Diameter is crucial for designing circular objects (pipes, wheels), calculating material needs, and understanding circular motion.