Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.7)
// Compass (v1.0.1)
// ----

$base-font-size: 16;

//Function to calculate rem value from expected pixel value   
@function rem($values...) {
  // How many values must we loop through?
  $length: length($values);
  // Variable to hold our final values
  $output: '';
  
  @for $i from 1 through $length {
    $value: nth($values, $i);
    
    // If value is 0 or auto, preserve it as is
    @if $value == 0 or $value == auto {
      $output: #{$output + $value};
    }
    @else {
      // Convert input "base-pixel-value" to corresponding rem value
      $value: $value/$base-font-size;
      $output: #{$output + $value}rem;
    }
    
    // Unless it's the last value, add a whitespace
    @if $i < $length {
      $output: #{$output + " "};
    }
  }
  
  @return $output;
}
  
.foo {
  font-size: rem(14);
  padding: rem(16, auto, 0, 10);
}

SassMeister-output.css

.foo {
  font-size: 0.875rem;
  padding: 1rem auto 0 0.625rem;
}