title: Calculated Item for Calculating Memory Usage as a Percentage in Zabbix
body: <p>In Zabbix I am trying to show total memory in use as a percentage.</p>
  
  <p>I try and create a calculated item with the formula:
  ((vm.memory.size[active])/(vm.memory.size[total]))*100</p>
  
  <p>This creates the item, yet when I check it's status it says "Not Supported".</p>
  
  <p>Is there something wrong with calculated item? This is just an example, but I've also had problems with creating calculated items, it always says "Not Supported".</p>