Font calculator mixin - sets font size, margin and font-size

font-calculator.scss

@function strip-units($number) {
  @return $number / ($number * 0 + 1);
}

// increases margin-bottom if font size is greater than 20px
@function double-size($fontSize, $marginNumber) {
  @if strip-units($fontSize) > 20  {
    @return $marginNumber * 1;
  } @else {
    @return $marginNumber;
  }
}

@function basefont-to-pixel($baseFS) {
  // see http://pxtoem.com/
  @if $baseFS == 37.5% {
    @return 6;
  } @else if $baseFS == 43.8% {
    @return 7;
  } @else if $baseFS == 50.0% {
    @return 8;
  } @else if $baseFS == 56.3% {
    @return 9;
  } @else if $baseFS == 62.5% {
    @return 10;
  } @else if $baseFS == 68.8% {
    @return 11;
  } @else if $baseFS == 75.0% {
    @return 12;
  } @else if $baseFS == 81.3% {
    @return 13;
  } @else if $baseFS == 87.5% {
    @return 14;
  } @else if $baseFS == 93.8% {
    @return 15;
  } @else if $baseFS == 100.0% {
    @return 16;
  }

}

@mixin font-calculator($fontFamily, $fontSize, $divider: null) {

  $fontSizeEm: strip-units($fontSize) / basefont-to-pixel($baseFontSize);
  font-size: #{$fontSizeEm}#{"em"};
  font-family: #{$fontFamily};

  @if $divider == 0 {
    $margin: null;
  } @else if $divider == 2 {
    $margin: (strip-units($baseLineHeight) / $fontSizeEm) * 2;
    margin-bottom: #{double-size($fontSize, $margin)}#{"em"};
  } @else if $divider == 1 {
    $margin: (strip-units($baseLineHeight) / $fontSizeEm);
    margin-bottom: #{double-size($fontSize, $margin)}#{"em"};
  } @else if $divider == 1.5 {
    $margin: (strip-units($baseLineHeight) / $fontSizeEm) * 1.5;
    margin-bottom: #{double-size($fontSize, $margin)}#{"em"};
  } @else if $divider == 0.5 {
    $margin: strip-units($baseLineHeight) / $fontSizeEm / 2;
    margin-bottom: #{double-size($fontSize, $margin)}#{"em"};
  } @else if $divider == 0.25 {
    $margin: strip-units($baseLineHeight) / $fontSizeEm / 4;
    margin-bottom: #{double-size($fontSize, $margin)}#{"em"};
  } @else if $divider == null {
    $margin: strip-units($baseLineHeight) / $fontSizeEm;
    margin-bottom: #{double-size($fontSize, $margin)}#{"em"};
  }

}