If you use FF4 and cannot view the ZohoSheet online calculators, there is now a workaround.  Click here!

In order to input your data, click the "Click to Edit" button.  Then, plug in the stat values you wish to test.
Be sure to select which spell/miracle boosting equipment you are wearing.

Note: Should you accidentally delete something important, simply reload the page to restart.
I apologize but this edit method is the best I can find currently.