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With numeric values in a vector, we can transform each into byte values with human readable units. The vec_fmt_bytes() function allows for the formatting of byte sizes to either of two common representations: (1) with decimal units (powers of 1000, examples being "kB" and "MB"), and (2) with binary units (powers of 1024, examples being "KiB" and "MiB").

It is assumed the input numeric values represent the number of bytes and automatic truncation of values will occur. The numeric values will be scaled to be in the range of 1 to <1000 and then decorated with the correct unit symbol according to the standard chosen. For more control over the formatting of byte sizes, we can use the following options:

  • decimals: choice of the number of decimal places, option to drop trailing zeros, and a choice of the decimal symbol

  • digit grouping separators: options to enable/disable digit separators and provide a choice of separator symbol

  • pattern: option to use a text pattern for decoration of the formatted values

  • locale-based formatting: providing a locale ID will result in number formatting specific to the chosen locale


  standard = c("decimal", "binary"),
  decimals = 1,
  n_sigfig = NULL,
  drop_trailing_zeros = TRUE,
  drop_trailing_dec_mark = TRUE,
  use_seps = TRUE,
  pattern = "{x}",
  sep_mark = ",",
  dec_mark = ".",
  force_sign = FALSE,
  incl_space = TRUE,
  locale = NULL,
  output = c("auto", "plain", "html", "latex", "rtf", "word")



A numeric vector.


The way to express large byte sizes.


An option to specify the exact number of decimal places to use. The default number of decimal places is 1.


A option to format numbers to n significant figures. By default, this is NULL and thus number values will be formatted according to the number of decimal places set via decimals. If opting to format according to the rules of significant figures, n_sigfig must be a number greater than or equal to 1. Any values passed to the decimals and drop_trailing_zeros arguments will be ignored.


A logical value that allows for removal of trailing zeros (those redundant zeros after the decimal mark).


A logical value that determines whether decimal marks should always appear even if there are no decimal digits to display after formatting (e.g, 23 becomes 23.). The default for this is TRUE, which means that trailing decimal marks are not shown.


An option to use digit group separators. The type of digit group separator is set by sep_mark and overridden if a locale ID is provided to locale. This setting is TRUE by default.


A formatting pattern that allows for decoration of the formatted value. The value itself is represented by {x} and all other characters are taken to be string literals.


The mark to use as a separator between groups of digits (e.g., using sep_mark = "," with 1000 would result in a formatted value of 1,000).


The character to use as a decimal mark (e.g., using dec_mark = "," with 0.152 would result in a formatted value of 0,152).


Should the positive sign be shown for positive numbers (effectively showing a sign for all numbers except zero)? If so, use TRUE for this option. The default is FALSE, where only negative numbers will display a minus sign.


An option for whether to include a space between the value and the units. The default of TRUE uses a space character for separation.


An optional locale ID that can be used for formatting the value according the locale's rules. Examples include "en" for English (United States) and "fr" for French (France). The use of a valid locale ID will override any values provided in sep_mark and dec_mark. We can use the info_locales() function as a useful reference for all of the locales that are supported.


The output style of the resulting character vector. This can either be "auto" (the default), "plain", "html", "latex", "rtf", or "word". In knitr rendering (i.e., Quarto or R Markdown), the "auto" option will choose the correct output value


A character vector.


Let's create a numeric vector for the next few examples:

num_vals <- c(3.24294e14, 8, 1362902, -59027, NA)

Using vec_fmt_bytes() with the default options will create a character vector with values in bytes. Any NA values remain as NA values. The rendering context will be autodetected unless specified in the output argument (here, it is of the "plain" output type).


#> [1] "324.3 TB" "8 B" "1.4 MB" "-59 kB" "NA"

We can change the number of decimal places with the decimals option:

vec_fmt_bytes(num_vals, decimals = 2)

#> [1] "324.29 TB" "8 B" "1.36 MB" "-59.03 kB" "NA"

If we are formatting for a different locale, we could supply the locale ID and gt will handle any locale-specific formatting options:

vec_fmt_bytes(num_vals, locale = "fi")

#> [1] "324,3 TB" "8 B" "1,4 MB" "-59 kB" "NA"

Should you need to have positive and negative signs on each of the output values, use force_sign = TRUE:

vec_fmt_bytes(num_vals, force_sign = TRUE)

#> [1] "+324.3 TB" "+8 B" "+1.4 MB" "-59 kB" "NA"

As a last example, one can wrap the values in a pattern with the pattern argument. Note here that NA values won't have the pattern applied.

vec_fmt_bytes(num_vals, pattern = "[{x}]")

#> [1] "[324.3 TB]" "[8 B]" "[1.4 MB]" "[-59 kB]" "NA"

Function ID