Excel includes several built-in trigonometric functions that make it easy to find the cosine, the sine or the tangent of a right-angled triangle.

The only problem is that these functions require the angles to be measured in *radians* rather than *degrees*, and while radians are a legitimate way of measuring angles — based on the radius of a circle — they are not something most people work with on a regular basis.

To help you get around this problem, Excel offers both the RADIANS() function, which converts degrees to radians, and the DEGREES() function, which does the opposite.

## The DEGREES Function's Syntax and Arguments

A function's syntax refers to the layout of the function and includes the function's name, brackets, and arguments.

The syntax for the DEGREES() function is:

=DEGREES(angle)

The *angle* argument specifies the angle, in degrees, to be converted to radians. Specify either a specific angle size (in radians) or a cell reference to the location where the angle size resides.

## Excel's DEGREES Function Example

Use the DEGREES() function to convert an angle of 1.570797 radians into degrees.

If you're rusty about manually entering formulas in Excel, check out our step-by-step formula tutorial for guidance.

In a cell, type:

=DEGREES(1.570797)

or, if the value were stored in cell A1, you could also type:

=DEGREES(A1)

And in either case, when you press **Enter** to execute the function, you should get a result of 90 degrees.

The DEGREES() function also supports point-and-click entry using a function dialog box.

## Alternative: Use the PI Formula

An alternative method that doesn't rely on the DEGREES() formula is to multiply the angle (in radians) by 180 then divide the result by the mathematical constant *pi*. For example, to convert 1.570797 radians to degrees, use the formula:

=1.570797*180/PI()

Pi, which is the ratio of a circle's circumference to its diameter, has a rounded value of 3.14 and is usually represented in formulas by the Greek letter *π*. Its value is expressed by the function PI(), which does not permit any arguments.

## Historical Note

Excel's trig functions use radians rather than degrees because when the program was first created, the trig functions were designed to be compatible with the trig functions in the spreadsheet program Lotus 1-2-3, which also used radians and which dominated the PC spreadsheet software market at the time.