pixels to em's sass function

_px2em.scss

// Your default font-size
$fs = 16;


@function px2em($target, $context: $fs) {
  @return ( ( 1 / $context ) * $target )+0em;
}

// ----------

body {
  font-size: 100%; // 16
}

#foo {
  margin-bottom: px2em($fs * 2); // 32px -> 2em
  .bar {
    font-size: px2em(14); // 0.875em
    margin-bottom: px2em($fs * 2, 14); // 14 given to px2em as $context, therefor -> 2.285em
  }
}