title: How to convert font size (in px) to the unit used in the document (mm) for svg
body: <p>I have svg created in inkscape <a href="https://gist.github.com/anonymous/00ed092d8a66a7d71ba006575ac82228" rel="nofollow noreferrer">here</a>.</p>
  
  <p>The document size is in <code>mm</code>. For the 2 text fields, the font size is given like this:</p>
  
  <pre><code>style="...;font-size:31.420084px;..."
  </code></pre>
  
  <p>So it is given in <code>px</code>. Now I want the size of the font related to the document size.</p>
  
  <p>But how should I convert the font-size in <code>px</code> to <code>mm</code>? I would need something like <code>dpi</code>, but the document does not specify anything.</p>