Radian is a measure based on radius of a circle that is used in mathematics especially in trigonometry. A degree, usually shown as °, is like a measuring unit for angles. It signifies a complete circle, which is 360 degrees in total.
When you want to do some trigonometric calculations in Excel, you may need to convert degree to radian or radian to degree. In Excel, there are two functions for this, called RADIANS and DEGREES.
RADIANS function in Excel
RADIANS function is a mathematical function that converts an angle in degrees to radians. For instance, it converts 180 degrees to the number of pi. After typing the function, select a cell or enter an angle.
The following formula converts 180 degrees to the number of pi.
=RADIANS (180)
90 degrees is converted to pi/2 with the formula below.
=RADIANS (90)
Convert angle in radians to degrees
To convert radian to degree, there is a mathematical built-in function called DEGREES in Excel. For instance, it converts number of pi to 180 degrees. After typing the function, simply select a cell or enter an radian value you want to convert to a degree.
The following formula =DEGREES (PI()) converts the number of PI to 180 degrees.
To get 360 degrees, use the formula as written below. This means that 2*pi radians represent a full circle.
=DEGREES (2*PI())
For 90 degrees, number of PI is divided by 2 as formula below.
=DEGREES (PI()/2)
RADIANS function and DEGREES function is available in Excel 2003 and later versions.