Circle Calculator
Calculate the area, circumference, and diameter of a circle.
Calculator Inputs
Results
Area
78.5398
Circumference
31.4159
Diameter
10
Circle Formulas Explained
A circle's properties are all determined by a single measurement: its radius. The radius is the distance from the center of the circle to any point on its edge. From this, we can calculate everything else.
Frequently Asked Questions
What is the formula for the area of a circle?
The area of a circle is calculated using the formula Area = π × r², where r is the radius.
What is the formula for the circumference of a circle?
The circumference is the distance around the circle, calculated as Circumference = 2 × π × r.