Excel TAN function
The TAN function is used to calculate the tangent of the given angle that is in radians. So, you should convert the angle to radians firstly when using the TAN function in Excel.
The syntax for the TAN function in Excel is:
If the number argument is in degrees, you should convert it to radians by RADIANS function or multiply the angle by PI()/180 firstly.
For instance, the number argument is 60 degree, to get the tangent value, please convert to radians firstly as this: RADIANS(60) or 60*PI() / 180.
Return the tangent value of an angle.
If you have a list of cells with degrees, to calculate the tangent, please use any one of the below formulas:
And then, drag the fill handle down to the cells you want to apply this formula, you can see all the tangent value have been calculated as following screenshot shown: