sass: getLineHeight function

getLineHeight.scss

$FontSize: 14px;
$LineHeight: $FontSize * 1.5;

@function getLineHeight($fontSize) {
  $height: $LineHeight;
  @while $height < $fontSize {
    $height: $height + $height;
  }
  @return $height;
}

//usage
p.para {
  font-size: $FontSize;
  line-height: getLineHieight($FontSize);
}