Circle Calculator
Calculate the properties of a circle such as radius, diameter, circumference, and area using any one known value. This calculator also computes the surface area of a sphere given its radius.
r = 10 cm
Circle Properties
| Radius (r) | 0 cm |
|---|---|
| Diameter (d) | 0 cm |
| Circumference (C) | 0 cm |
| Area (A) | 0 cm² |
Sphere Properties
| Surface Area | 0 cm² |
|---|
About the Circle Calculator
A circle is a simple closed shape in Euclidean geometry. It is the set of all points in a plane that are at a given distance from a given point, the center. The distance between any point of the circle and the center is called the radius.
Circle Formulas
The following formulas are used in this calculator:
- Diameter (d): d = 2r (twice the radius)
- Circumference (C): C = 2πr = πd (the perimeter of the circle)
- Area (A): A = πr² (the space enclosed by the circle)
- Sphere Surface Area: SA = 4πr² (for a three-dimensional sphere with the same radius)
How to Use the Calculator
To use this calculator:
- Select which property you know (radius, diameter, circumference, or area)
- Enter the known value
- Select the units (centimeters or inches)
- Click "Calculate" to compute all other circle properties
Practical Applications
Circle calculations are essential in many fields:
- Engineering: Designing circular components like pipes, wheels, and gears
- Construction: Calculating materials needed for circular structures
- Manufacturing: Determining dimensions for circular products
- Science: Calculating properties of circular or spherical objects
- Everyday Life: Measuring round objects like plates, tables, or gardens