Circle Calculator
Circle area, circumference, radius.
Result
Area
78.54sq units
- Circumference
- 31.416
Common questions
How do I calculate the area and circumference of a circle?
Area = π × r². Circumference = 2π × r. Enter the radius (or diameter) and the calculator provides both values instantly.
How do I find the radius from the area?
Radius = √(Area ÷ π). For example, if the area is 50 square units: r = √(50/π) ≈ 3.99 units.