Creating a Stacked Percentage Bar Chart in R with ggplot with labels

Here an example using the mtcars dataset where you can calculate the percentage per group and use these to place in your bars using label with geom_text like this:

library(ggplot2)
library(dplyr)
mtcars %>%
  group_by(am, vs) %>%
  summarise(cnt = n()) %>%
  mutate(perc = round(cnt/sum(cnt), 2)) %>%
  ggplot(aes(x = factor(vs), fill = factor(am), y = perc)) + 
  geom_col(position = 'fill') +
  geom_text(aes(label = paste0(perc*100,"%"), y = perc), position = position_stack(vjust = 0.5), size = 3) +
  labs(fill = 'Class', x = 'vs') +
  scale_y_continuous(limits = c(0,1))
#> `summarise()` has grouped output by 'am'. You can override using the `.groups`
#> argument.

^{Created on 2022-11-02 with reprex v2.0.2}