Circumference of a circle

The constant π appears in many math formulas relating to the circle. The formula for the circumference of a circle is 2πr. Given a radius of 3, the same formula in Excel is:

Area of a circle

The area enclosed by a circle with radius (r) is defined by the following formula: πr2. With radius in cell A1, the same formula in Excel with the PI() function is:

Radians to degrees

To convert an angle measured in radians in terms of π, the DEGREES function can be used to get the corresponding angle in degrees: See for a more detailed explanation of key math concepts and formulas. 

Dave Bruns

Hi - I’m Dave Bruns, and I run Exceljet with my wife, Lisa. Our goal is to help you work faster in Excel. We create short videos, and clear examples of formulas, functions, pivot tables, conditional formatting, and charts.