Format Numbers as Percentages in R (With Examples)

The easiest way to format numbers as percentages in R is to use the percent() function from the scales package. This function uses the following syntax:

percent(x, accuracy = 1)

where:

• x: The object to format as a percentage.
• accuracy: A number to round to. For example, use .01 to round to two decimal places.

This tutorial provides several examples of how to use this function in practice.

Example 1: Format Percentages in a Vector

The following code shows how to format numbers as percentages in a vector:

library(scales)

#create data
data <- c(.3, .7, .14, .18, .22, .78)

#format numbers as percentages
percent(data, accuracy = 1)

[1] "30%" "70%" "14%" "18%" "22%" "78%"

#format numbers as percentages with one decimal place
percent(data, accuracy = 0.1)

[1] "30.0%" "70.0%" "14.0%" "18.0%" "22.0%" "78.0%"

#format numbers as percentages with two decimal places
percent(data, accuracy = 0.01)

[1] "30.00%" "70.00%" "14.00%" "18.00%" "22.00%" "78.00%"

Example 2: Format Percentages in a Data Frame Column

The following code shows how to format numbers as percentages in a column of a data frame:

library(scales)

#create data frame
df = data.frame(region = c('A', 'B', 'C', 'D'),
                growth = c(.3, .7, .14, .18))

#view data frame
df

  region growth
1      A   0.30
2      B   0.70
3      C   0.14
4      D   0.18

#format numbers as percentages in growth column
df$growth <- percent(df$growth, accuracy=1)

#view updated data frame
df

  region growth
1      A    30%
2      B    70%
3      C    14%
4      D    18%

Example 3: Format Percentages in Multiple Data Frame Columns

The following code shows how to format numbers as percentages in multiple columns of a data frame:

library(scales)

#create data frame
df = data.frame(region = c('A', 'B', 'C', 'D'),
                growth = c(.3, .7, .14, .18),
                trend = c(.04, .09, .22, .25))

#view data frame
df
  region growth trend
1      A   0.30  0.04
2      B   0.70  0.09
3      C   0.14  0.22
4      D   0.18  0.25

#format numbers as percentages in growth and trend columns
df[2:3] <- sapply(df[2:3], function(x) percent(x, accuracy=1))

#view updated data frame
df

  region growth trend
1      A    30%    4%
2      B    70%    9%
3      C    14%   22%
4      D    18%   25%

You can find more R tutorials on this page.