๐ Geometry
Area of a Circle Calculator
A circleโs area is ฯ times the radius squared. Because the radius is squared, doubling it quadruples the area โ a relationship that surprises people when comparing pizza sizes.
How it works
Radius used
Diameter
Area
Circumference
Diameter
Radius used
Frequently asked questions
How do I use the Area of a Circle Calculator?
Fill in the fields above โ the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.