1. What is the Circumference Formula?

The circumference (C) of a circle is calculated using the formula C = π × D, where D is the diameter of the circle and π (pi) is approximately 3.14159. This fundamental relationship connects a circle's linear dimension (diameter) with its perimeter (circumference).

2. How Does the Calculator Work?

The calculator uses the circumference formula:

Where:

• \( C \) — Circumference of the circle
• \( D \) — Diameter of the circle
• \( \pi \) — Mathematical constant (~3.14159)

Explanation: The calculator can compute either value when the other is provided. Enter either diameter to get circumference, or circumference to get diameter.

3. Importance of Diameter and Circumference

Details: These measurements are essential in engineering, construction, manufacturing, and many scientific applications where circular objects or motion are involved.

4. Using the Calculator

Tips: Enter either diameter or circumference (leave the other field empty). Values must be positive numbers. The calculator will compute the missing dimension.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between diameter and radius?
A: Diameter is the distance across the circle through its center, while radius is half the diameter (distance from center to edge).

Q2: Can I calculate radius from this?
A: Yes, radius (r) = D/2 or r = C/(2π). You can easily convert the results.

Q3: How precise is the π value used?
A: The calculator uses PHP's built-in pi() function which provides about 14 decimal digits of precision.

Q4: What units should I use?
A: The calculator works with any consistent units (meters, inches, etc.). Just be sure to interpret results in the same units.

Q5: Why does my manual calculation differ slightly?
A: Small differences may occur due to rounding. The calculator uses full precision until final display.