Blog Post

Em Units are Your Friend

Use ems for (almost) everything. Em is a proportional unit that begins as equal to the default font size. If the user ups (or lowers) their font size, ems will scale up or down accordingly. This makes them great for margin and padding as well as for your breakpoints in Responsive Design. About the only thing you wouldn’t want to use them for is widths of elements. Use percentages for those so that they can properly respond to different screen sizes.