Purpose
Return value
Syntax
=RADIANS(angle)- angle - Angle in degrees to convert to radians.
How to use
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
Explanation
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...
Notes
- 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).
Related functions
DEGREES Function
The Excel DEGREES function converts angles (expressed in radians) to degrees. For example, the formula =DEGREES(PI()) returns 180.
PI Function
The Excel PI function returns the value of the geometric constant π (pi). The value represents a half-rotation in the radian angle system. The constant appears in many formulas relating the circle, such as the area of a circle....
