# How to Convert a Factor to Numeric in R

Basic R Syntax:

`x_num <- as.numeric(as.character(x))`

More explanations needed? You’ll find all relevant information for the conversion of R factors to numeric in the following tutorial.

## Example: Convert Factor to Numeric in R

To convert a factor to numeric in R can be a tricky task. In the following, I’m therefore going to explain how to convert a factor vector to numeric properly without a loss of information.

Before we can start, we need to create an example factor vector in R:

```set.seed(13579)                                            # Set seed
x <- as.factor(sample(c(3, 5, 6, 9), 100, replace = TRUE)) # Example factor vector```

Our factor vector consists of the four categories 3, 5, 6 & 9:

`x                                                          # Print x to RStudio console` Graphic 1: Example Factor Vector Printed to the RStudio Console

So, how can we transform this factor vector to numeric?

```x_num <- as.numeric(as.character(x))                       # Convert factor to numeric
x_num                                                      # Print converted x to RStudio console
# 3 9 3 9 5 5 3 9 9 3 9 9 9...```

That’s it! Easy, right?

However, please note that – before the conversion to numeric – it is important to transform the factor to character first (as shown in the example above).

I’ll show you why this preliminary step is needed:

```x_wrong <- as.numeric(x)                                   # Wrong conversion to numeric
x_wrong                                                    # Print wrongly converted x to RStudio console
# 1 4 1 4 2 2 1 4 4 1 4 4 4...```

1? 4?! 22??? What happened?! Why does the converted vector consist of wrong values?

The answer is simple: R automatically assigns the numbers 1, 2, 3, 4, and so on to the categories of our factor. If we want to hinder R from doing so, we need to convert the factor to character first.

Keep this in mind, when you convert a factor vector to numeric! I’ve seen this mistake quite often in the past.

## Programming Video: Further Examples

Check out the following video, in case you need further explanations and examples for the transformation of factors to numerical vectors. I demonstrate the code of this tutorial in the video:

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Would you like to learn more about data type conversion in R? Then, you might also have a look at the following video that I have published on my YouTube channel.

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## Alternative Programming Codes

I’ve shown you the most popular way to convert factor to numeric in R. However, there are several alternative ways to achieve this transformation:

Alternative 1: The levels R function

```x_alt1 <- as.numeric(levels(x)[x])                         # Use the levels R function
x_alt1                                                     # Print to R console```

Alternative 2: The paste R function

```x_alt2 <- as.numeric(paste(x))                             # Use the paste R function
x_alt2                                                     # Print to R console```

Alternative 3: The unfactor R function of the varhandle package

```install.packages("varhandle")                              # Install varhandle package

x_alt3 <- unfactor(x)                                      # Use the unfactor R function
x_alt3                                                     # Print to R console```