title: Adding XXL & XXXL breakpoints. What is container-max-widths?
body: <p>I want to add XXL and XXXL break points in bootstrap 4.x</p>
  
  <pre><code>$grid-breakpoints: (
      xs: 0,
      sm: 576px,
      md: 768px,
      lg: 992px,
      xl: 1200px,
      xxl: 1440px,
      xxxl: 1600px
    );
  </code></pre>
  
  <p>I know I need to also set the $container-max-widths, but I am not sure what the math is. I think it has something to do with the 30px margin. What is the math to calculate that and/or what is the numbers I should use for XXL and XXXL</p>
  
  <pre><code>$container-max-widths: (
      sm: 540px,
      md: 720px,
      lg: 960px,
      xl: 1140px,
      xxl:  ????,
      xxxl: ????
    )
  </code></pre>
  
  <p>Why is it 720 for 768? <strong>What I really want to know is what do I put in for XXL(1440) and XXXL(1600)?</strong></p>