Circle Calculator
Type a value into any field below - radius, diameter, circumference, or area - and every other property is solved instantly. Add a central angle to get the sector area and arc length.
Enter a non-negative number in the field you are editing to solve the circle.
Circle measurements
Edit any one field - the other three update as you type.
Diagram
The shaded wedge follows the central angle below.
Sector & arc
Enter a central angle in degrees to slice the circle into a sector.
Sector area
19.63495408
Arc length
7.85398163
Formulas used
| Quantity | Formula |
|---|---|
| Diameter | d = 2r |
| Circumference | C = 2πr = πd |
| Area | A = πr² |
| Sector area | (θ ÷ 360) × πr² |
| Arc length | (θ ÷ 360) × 2πr |
π ≈ 3.141592653589793 (Math.PI)
We can't find the internet
Attempting to reconnect
Something went wrong!
Attempting to reconnect