Here are a few options for changing text / label sizes
library(ggplot2)
# Example data using mtcars
a <- aggregate(mpg ~ vs + am , mtcars, function(i) round(mean(i))) p <- ggplot(mtcars, aes(factor(vs), y=mpg, fill=factor(am))) + geom_bar(stat="identity",position="dodge") + geom_text(data = a, aes(label = mpg), position = position_dodge(width=0.9), size=20) The size in the geom_text changes the size of the geom_text labels. p <- p + theme(axis.text = element_text(size = 15)) # changes axis labels p <- p + theme(axis.title = element_text(size = 25)) # change axis titles p <- p + theme(text = element_text(size = 10)) # this will change all text size # (except geom_text) For this And why size of 10 in geom_text() is different from that in theme(text=element_text()) ? Yes, they are different. I did a quick manual check and they appear to be in the ratio of ~ (14/5) for geom_text sizes to theme sizes. So a horrible fix for uniform sizes is to scale by this ratio geom.text.size = 7 theme.size = (14/5) * geom.text.size ggplot(mtcars, aes(factor(vs), y=mpg, fill=factor(am))) + geom_bar(stat="identity",position="dodge") + geom_text(data = a, aes(label = mpg), position = position_dodge(width=0.9), size=geom.text.size) + theme(axis.text = element_text(size = theme.size, colour="black")) This of course doesn't explain why? and is a pita (and i assume there is a more sensible way to do this)