Circle Calculator

Calculate circle properties including area, circumference, diameter, and radius. Essential for mathematics, engineering, and design.

How to Use Circle Calculator

1. 1.**Enter any one value**: radius, diameter, or circumference
2. 2.**Click "Calculate Circle"** to get all properties
3. 3.**View results** for all circle measurements
4. 4.**Use any input** to calculate the others

Features

• •**Multiple Inputs**: Use radius, diameter, or circumference
• •**Complete Results**: Calculate all circle properties
• •**Real-time Calculation**: Instant results
• •**Formula Display**: Shows calculation methods

Circle Formulas

Area

A = π × r²

Circumference

C = 2 × π × r

Diameter

D = 2 × r

Radius

r = D/2 = C/(2π)

Circle Properties

• •**Radius**: Distance from center to edge
• •**Diameter**: Distance across the circle through center
• •**Circumference**: Distance around the circle
• •**Area**: Space inside the circle
• •**Pi (π)**: Approximately 3.14159

Common Applications

• •**Construction**: Circular foundations, pipes, tanks
• •**Design**: Round tables, wheels, logos
• •**Engineering**: Gears, bearings, pulleys
• •**Mathematics**: Geometry problems, proofs
• •**Everyday**: Pizza, cakes, circular objects

Practical Examples

• •**Pizza**: 12" diameter = 6" radius = 113.1 sq in area
• •**Wheel**: 24" diameter = 75.4" circumference
• •**Pipe**: 4" radius = 8" diameter = 50.3" circumference
• •**Garden**: 10' radius = 314.2 sq ft area

Tips for Using Circle Calculator

• •**Use consistent units** for all measurements
• •**Enter any one value** to calculate others
• •**Round appropriately** for practical applications
• •**Consider tolerances** for manufacturing
• •**Add waste factor** for materials

Circle Facts

• •**Pi is irrational**: Never-ending decimal
• •**Circle has infinite symmetry**: Looks the same from any angle
• •**Maximum area**: Circle has maximum area for given perimeter
• •**Constant ratio**: Circumference to diameter is always π

Unit Conversions

• •**1 foot** = 12 inches
• •**1 meter** = 3.281 feet
• •**1 inch** = 2.54 centimeters
• •**π radians** = 180 degrees