Radians and degrees are both units used for measuring angles. The circle is comprised of 2π radians, which is the equivalent of 360°. We often come across the scenarios in mathematical calculations in which we need to convert degrees to radians and radians to degrees. Fortunately, R provides packages that do this exactly. Let’s see how to do it.

**Convert Radians to Degrees in R**

To convert radian values to degrees in R, use the **rad2deg()** function. The rad2deg() is a **grid **library’s function that calculates radians from degrees.

**Syntax**

`rad2deg(rad)`

**Parameters**

The **rad2deg() **method accepts a number in radian.

**Example**

To work with the rad2deg() function, you must install the **REdaS package **in your system.

The next step will be to create an R file and import the library using the following code.

`library(REdaS)`

Now, we can use the rad2deg() function to convert radian to degree values.

Take three-radian values and convert them to degrees.

```
library(REdaS)
rad2deg(pi)
rad2deg(3.14)
rad2deg(22 / 7)
```

The pi is a built-in constant in R.

**Output**

```
Loading required package: grid
[1] 180
[1] 179.9087
[1] 180.0724
```

As you can see that the degree values of **pi, 3.14, **and **22/7 **are **180**, **179.9087**, and **180.0724**.

## Converting radians to degrees using units package

There is another third-party package called **units** that provides a function that will convert the radian values to degrees.

The next step is to import the **units** library using the following code.

`library(units)`

Now, we can use the** as_units()** and **set_units()** functions to convert radian to degree values.

```
library(units)
pi_rad <- as_units(pi, "radians")
pi_deg <- set_units(pi_rad, "degrees")
pi_deg
```

**Output**

`180 [°]`

And we get the 180* value from the radian value.

**Writing your own functions to convert radians to degrees.**

Although it is always preferred to use the built-in or library-provided functions for conversion but, out of curiosity, you can create your own functions too. Let’s see how to create it.

**Converting radians to degrees**

```
rad2deg <- function(rad) {
(rad * 180) / (pi)
}
```

Now, you can call the function and pass the values in the form of a radian, and it will return the value in degree.

```
rad2deg <- function(rad) {
(rad * 180) / (pi)
}
rad2deg(pi)
rad2deg(3.14)
rad2deg(22 / 7)
```

**Output**

```
[1] 180
[1] 179.9087
[1] 180.0724
```

**Converting degrees to radians**

Let’s create a custom function in R that converts degrees to radians.

```
deg2rad <- function(deg) {
(deg * pi) / (180)
}
```

Now, you can call the function and pass the values in the form of degree, and it will return the value in radian.

```
deg2rad <- function(deg) {
(deg * pi) / (180)
}
deg2rad(180)
deg2rad(179.9087)
deg2rad(180.0724)
```

**Output**

```
[1] 3.141593
[1] 3.139999
[1] 3.142856
```

That is it for converting radians to degrees in R tutorial.

Krunal Lathiya is an Information Technology Engineer by education and web developer by profession. He has worked with many back-end platforms, including Node.js, PHP, and Python. In addition, Krunal has excellent knowledge of Data Science and Machine Learning, and he is an expert in R Language. Krunal has written many programming blogs, which showcases his vast expertise in this field.