The number of grid columns can be modified via Sass variables. `$grid-columns` is used to generate the widths (in percent) of each individual column while `$grid-gutter-width` allows breakpoint-specific widths that are divided evenly across `padding-left` and `padding-right` for the column gutters.
{% highlight scss %}
-$grid-columns: 12 !default;
-$grid-gutter-width: 30px !default;
+$grid-columns: 12 !default;
+$grid-gutter-width: 30px !default;
{% endhighlight %}
### Grid tiers