The Excel RADIANS function converts degrees to radians. For example, =RADIANS(180) returns 3.1415 or the value of π (pi).


Converts degrees into radians

Return value 



  • angle - Angle in degrees to convert to radians.



Usage notes 

The RADIANS function takes an angle in degrees and converts it to radians. Radians measure angles using the radius of a circle. For example, to convert a 45 degree angle to radians the formula is:

=RADIANS(45) // Returns 0.785 or π/4


Radians are a unit of measure for circles

One radian is equal to the amount of rotation required to travel one radius along the circumference of the circle, as seen in the image above. A full-rotation or 360° in radians is equal to the value of 2π. A half-rotation or 180° in radians is equal to the value of geometric constant π (pi).

= RADIANS(360) =2*PI() // A full rotation is 6.283...
= RADIANS(180) =PI() // A half rotation is 3.141...


  • To convert radians to degrees, see the DEGREES function.
  • A full-rotation (360°) in radians is equal to 6.283 or 2π
  • A half-rotation (180°) in radians is equal to 3.142 or π (pi).
Dave Bruns Profile Picture

AuthorMicrosoft Most Valuable Professional Award

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.