How to format numbers with commas in R

Adding commas as thousand separators makes large numbers easier to read.

With base R

Use format() with big.mark = ",":

x <- c(1000, 1234567.89, 999999)

format(x, big.mark = ",")
# [1] "1,000"       "1,234,567.89" "999,999"

# For currency-like formatting
format(x, big.mark = ",", decimal.mark = ".", nsmall = 2)
# [1] "1,000.00"       "1,234,567.89" "999,999.00"

With scales

The scales package provides convenient wrappers:

library(scales)

x <- c(1000, 1234567.89, 999999)

comma(x)
# [1] "1,000"       "1,234,567.89" "999,999"

dollar(x)      # Adds $ prefix
# [1] "$1,000"       "$1,234,567.89" "$999,999"

percent(0.123) # Formats as percentage
# [1] "12.3%"

With dplyr and ggplot2

Apply formatting directly in pipelines:

library(dplyr)

df <- data.frame(
  product = c("Widget A", "Widget B", "Widget C"),
  sales = c(1500, 2345678, 99999)
)

df %>%
  mutate(sales_formatted = comma(sales))

With formattable

For prettier tables:

library(formattable)

x <- account(c(1000, 1234567.89, -500))
format(x, digits = 2)
# [1] "1,000.00"       "1,234,567.89" "-500.00"

currency(x)
# [1] "$1,000.00"       "$1,234,567.89" "$-500.00"

In ggplot2 labels

library(ggplot2)

ggplot(df, aes(x = product, y = sales)) +
  geom_bar(stat = "identity") +
  scale_y_continuous(labels = comma)

See Also

• format() — Base R formatting
• sprintf() — C-style formatting
• paste() — String concatenation