Microsoft Excel 2010 contains a large number of mathematical functions you can use on your data. If you need to determine the tangent of a given angle, you can utilize Excel's "TAN" function to get your result. The TAN function, like the "SIN" and "COS" functions, can only compute the angle if it is expressed in radians, as opposed to degrees. You can convert your degrees to radians by dividing 360 by two times pi, and then multiplying the result by your number of degrees or you can simply use Excels "RADIANS" function to automatically convert your degrees into radians.

Open up the Excel worksheet where you want to use Excel's tangent function.

Select the cell where you want to determine the tangent of an angle.

Enter in the following formula:
=TAN(X)
where "X" equals the angle you want the tangent for, in radians. If "X" is listed in another cell, you can instead use a cell reference, like A1 or B12 for "X." If your angle information is in degrees, use this formula instead:
=TAN(RADIANS(X))
as the RADIANS formula will convert the angle to radians.
Tips & Warnings
 Excel also has a formula to find hyperbolic tangents. You use this formula the same way that you would use the normal tangent formula, but use "TANH" instead of TAN.