The first detailed sizing information on Exchange Server 2013 has appeared in the Exchange Team Blog:
There is not yet a calculator like Exchange 2010, but according to the article this is still to come. Since I wanted to make my life a little easier, I made a little Excel table myself, but I'm not 100% sure whether I've implemented the formulas correctly, so we'll see what the load tests reveal.
When the official sizing calculator is published, this will be superfluous anyway.
If you still want to have the table, you can download it here:
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