title: Specify width in *characters*
body: <p>When using a <strong>fixed width font</strong>, I'd like to specify the width of an HTML element in <em>characters</em>.</p>
  
  <p>The "em" unit is supposed to be the width of the M character, so I should be able to use it to specify a width. This is an example:</p>
  
  <pre><code>&lt;html&gt;
    &lt;head&gt;
      &lt;style&gt;
        div {
          font-family: Courier;
          width: 10em;
        }
      &lt;/style&gt;
    &lt;/head&gt;
    &lt;body&gt;
      &lt;div&gt;
        1 3 5 7 9 1 3 5 7 9 1
      &lt;/div&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>The result is not what I wanted as the browser line breaks after column 15, not 10:</p>
  
  <pre><code>1 3 5 7 9 1 3 5
  7 9 1
  </code></pre>
  
  <p>(Result in Firefox and Chromium, both in Ubuntu.)</p>
  
  <p><a href="https://secure.wikimedia.org/wikipedia/en/wiki/Em_%28typography%29" rel="noreferrer">Wikipedia's article</a> says that an "em" is not always the width of an M, so it definitely looks like the "em" unit can't be trusted for this.</p>