Circle Calculator

Calculate area, circumference, diameter and other properties of a circle with our easy-to-use calculator.

Understanding Circle Properties

Our Circle Calculator allows you to quickly find all the key properties of a circle based on just one measurement. This tool is perfect for students, engineers, designers, and anyone working with circular shapes.

Key Circle Formulas

  • Radius (r): The distance from the center of the circle to any point on its circumference.
  • Diameter (d): d = 2r - The distance across the circle passing through the center.
  • Circumference (C): C = 2πr = πd - The total distance around the circle.
  • Area (A): A = πr² - The total space enclosed by the circle.

Applications of Circle Properties:

In Mathematics:

  • Geometry calculations
  • Trigonometry
  • Calculus applications
  • Pi (π) approximations
  • Coordinate geometry

In Real-World Applications:

  • Engineering designs
  • Architecture planning
  • Construction projects
  • Manufacturing
  • Land surveying

How to Use the Calculator:

  1. Select the type of measurement you know (radius, diameter, circumference, or area)
  2. Enter the value of your known measurement
  3. Choose the appropriate unit of measurement
  4. Select your preferred decimal precision
  5. Choose the Pi (π) value approximation you want to use
  6. Click "Calculate Circle Properties" to see all results

Advanced Circle Concepts

Beyond the basic properties, circles have many interesting properties:

  • Sectors and Segments: Parts of a circle formed by arcs and chords
  • Central Angles: Angles formed at the center of a circle
  • Inscribed Angles: Angles formed by two chords that meet on the circle
  • Tangent Lines: Lines that touch the circle at exactly one point
  • Circle Theorems: Various geometric principles relating to circles