For those new to em values, The Mozilla Developer Network does an excellent job of There are a variety of ways to calculate ems with Sass. If you use rems for setting font sizes, here's a tiny tool to calculate the rem sizes you need for your css. Choose your font-size (px). px sizes to convert. With this method of calculation, in a CSS file there is no strict definition for what an ' em ' is; it all depends on what else is going on in your.
Calculate em Video