Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.4)
// Compass (v1.0.1)
// ----

$col-map: ();
@mixin col-span($cols, $total) {
  $width: ($cols/$total) * 100%;
  @if map-has-key($col-map, $width) {
    @extend map-get($col-map, $width);
  }
  @else {
    width: $width;
    $col-map: map-merge($col-map, ($width: nth(&, 1)));
  }
}

.col-1-2 { @include col-span(1, 2) }
.col-1-3 { @include col-span(1, 3) }
.col-2-3 { @include col-span(2, 3) }
.col-1-4 { @include col-span(1, 4) }
.col-2-4 { @include col-span(2, 4) }
.col-3-4 { @include col-span(3, 4) }
.col-1-5 { @include col-span(1, 5) }
.col-2-5 { @include col-span(2, 5) }
.col-3-5 { @include col-span(3, 5) }
.col-4-5 { @include col-span(4, 5) }
.col-1-6 { @include col-span(1, 6) }
.col-2-6 { @include col-span(2, 6) }
.col-3-6 { @include col-span(3, 6) }
.col-4-6 { @include col-span(4, 6) }
.col-5-6 { @include col-span(5, 6) }

SassMeister-output.css

.col-1-2 {
  width: 50%;
}

.col-1-3 {
  width: 33.33333%;
}

.col-2-3 {
  width: 66.66667%;
}

.col-1-4 {
  width: 25%;
}

.col-2-4 {
  width: 50%;
}

.col-3-4 {
  width: 75%;
}

.col-1-5 {
  width: 20%;
}

.col-2-5 {
  width: 40%;
}

.col-3-5 {
  width: 60%;
}

.col-4-5 {
  width: 80%;
}

.col-1-6 {
  width: 16.66667%;
}

.col-2-6 {
  width: 33.33333%;
}

.col-3-6 {
  width: 50%;
}

.col-4-6 {
  width: 66.66667%;
}

.col-5-6 {
  width: 83.33333%;
}