simple rem/px Sass mixin

rem-px.scss

html {
  font-size: 62.5%; // setting the doc base as 10px = 1.0rem
}

@mixin rem($property, $value) {
  #{$property}: $value * 1px;
  #{$property}: $value * .1rem;
}


/*  
  @include rem(font-size, 20);
  will output: 
  font-size: 20px;
  font-size: 2.0rem;
*/