Sass pixel to rem unit converter set by Nicole O'Sullivan

font_size.scss

// converting a px based font-size to rem
@function calculate-rem($size) {
  $rem-size: $size / $default-font-size;
  @return #{ $rem-size }rem;
}
@mixin font-size($size) {
  font-size: $size;
  font-size: calcuate-rem($size);
}