title: Calculating values with formulae from user input in PHP
body: <p>I want to do an equation using the values I get from the input boxes called ampMin, voltMin and hastMin...</p>
  
  <p>I'm not sure if it's a syntax problem or my method of approach is plain wrong.. Here's is an example of how the equation should look and work like with Excel.</p>
  
  <p>What am I doing wrong? Thank you for your time!</p>
  
  <p>EDIT: worth mentioning is that the whole block of code is within "strckenergi.php".</p>
  
  <p><img src="https://i.stack.imgur.com/uveBg.png" alt="Excel equation for Qmax"></p>
  
  <pre><code>&lt;html&gt;
  &lt;title&gt;Sträckenergi&lt;/title&gt;
  &lt;body&gt;
      &lt;h3&gt;Svetsmetod: 111&lt;/h3&gt;
      &lt;h4&gt;&lt;i&gt;Med K=0.8&lt;/i&gt;&lt;/h4&gt;
      &lt;pre&gt;
          &lt;form method="post" action="strckenergi.php"&gt;
              Amp. Min &lt;input type="text" name="ampMin"&gt;  Volt. Min &lt;input type ="text" name="voltMin"&gt; Hast. Min &lt;input type="text" name="hastMin"&gt; &lt;/pre&gt;
          &lt;?php
          echo "kJ/mm (minimum) = " . $qMin
          $qMin = ( $ampMin * $voltMin ) / (( $hastMin * 1000 ) / $hastMin * 0.8));
          ?&gt;  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>