title: Calculations on client machine or on the server?
body: <p>I will try to make this question as clear as I can but bare in mind that English is not my first language. I have a web application written in PHP using a MySQL database. In a table I might have thousands of entries and in each entry I am storing this data:</p>
  
  <pre><code>$hourly_rate,
  $minutes
  </code></pre>
  
  <p>when I process my table through a loop, I calculate the net value using the following formula:</p>
  
  <pre><code>$net_value = $minutes*($hourly_rate/60);
  </code></pre>
  
  <p>now the question, should I instead add a $net_value field on my table, calculate the net value on the client side using JQUERY and then upload the result of the calculation in the $net_value field? Which one do you think is the best approach considering I might have 1000 users accessing the system at the same time?</p>
  
  <p>Thank you for you help,</p>
  
  <p>Donato</p>