Before you can use the calculator, install the latest Java and then add http://www.poologic.com (this exact url syntax) to the Exception Site List.

The Exception Site List is on the Security tab of the Java Control Panel.  The Java Control Panel is one of the items on the Control Panel on Microsoft Windows systems (or it may be on subordinate list accessed from the Control Panel).  For more information, follow these instructions

Click here to proceed to the calculator