Again the Microsoft Exchange Team worked hard to improve the Exchange Mailbox Role Calculator even more with the release of version 6.1,  1 month after the 4.5 update. This version includes the following enhancements since 4.5:

• Option to select requested storage design, also to prevent logic issues with the calculator suggesting 0 (zero) disks. You have the option to select the storage design As Calculated, Entirely on RAID or Entirely on JBOD;
• Simplified messaging profiles (e.g. “100 messages” instead of “20 sent/80 received”) as it doesn’t influence the IO and capacity calculations;
• Some improvements and additions in layout and information displayed (e.g. Environment Configuration, Role Requirements Results).

For an extensive overview of the changes and fixes (e.g. zero disk issue), consult the Exchange Team’s changeblog here.

You can download the calculator here. Instructions on usage can be found here.