How to Add Dollar Symbol for Axis Labels with ggplot2?

In this tutorial, we will learn how to format x or y-axis so that we have dollar symbol in a plot made with ggplot2 in R.

Let us create a dataframe with salary education information for developers using the StackOverflow survey results. We first create two lists; one for education and the second for salary.

education <- c("Bachelor's", "Less than Bachelor's",
               "Master's","PhD","Professional")
salary <- c(110000,105000,126000,144200,95967)

We create a tibble using the two lists with tibble() function.

df <- tibble(Education=education,
             Salary=salary)
df
## # A tibble: 5 x 2
##   Education            Salary
##   <chr>                 <dbl>
## 1 Bachelor's           110000
## 2 Less than Bachelor's 105000
## 3 Master's             126000
## 4 PhD                  144200
## 5 Professional          95967

Let us make a simple bar plot with geom_col() in ggplot2.

df %>%
  ggplot(aes(x=Education, y=Salary)) +
  geom_col()

In the barplot, height of bars represent salary for each education category.

Note that on y-axis we have the salary as numbers. Instead, sometimes you would like to have the y-axis with dollars. We can use the R Package scales to format with dollar symbol.

We can do that by specifying scale_y_continuous() with labels=scales::dollar_format()

df %>%
  ggplot(aes(x=Education, y=Salary)) +
  geom_col()+
  scale_y_continuous(labels=scales::dollar_format())

Now, we get a bar plot with y-axis formatted with dollars.