Circle Calculator

Calculate circle measurements instantly. Enter any single measurement (radius, diameter, circumference, or area) and get all other measurements automatically. Includes visual representation and precise calculations.

Circle Calculator

Calculate circle measurements instantly with our free online circle calculator. Find the radius, diameter, circumference, and area of any circle.

Features

  • Calculate all circle measurements from any single input
  • Real-time calculations
  • Visual circle representation
  • Precise results up to 4 decimal places
  • Mobile-friendly interface
  • No registration required

How to Use

  1. Choose what value you know (radius, diameter, circumference, or area)
  2. Enter the value in the input field
  3. Get instant results for all other measurements
  4. See the visual representation update in real-time

Circle Formulas

Basic Relationships

  • Diameter = 2 × Radius
  • Circumference = 2 × π × Radius
  • Area = π × Radius²

Converting Between Measurements

  • Radius from Diameter: r = d ÷ 2
  • Radius from Circumference: r = C ÷ (2π)
  • Radius from Area: r = √(A ÷ π)

Common Applications

Engineering

  • Designing circular components
  • Calculating pipe dimensions
  • Planning circular structures

Mathematics

  • Geometry problems
  • Mathematical modeling
  • Educational demonstrations

Real World

  • Calculating fence lengths for circular areas
  • Determining material needed for circular objects
  • Planning circular gardens or pools

Why Use Our Calculator

  • Instant calculations
  • All measurements from one input
  • Visual feedback
  • High precision
  • User-friendly interface
  • Works offline
  • Free to use