If you checked out the PSU calculator we shared with you and wished it had a more detailed selection process for really granular and precise control you'll definitely want to check out the eXtreme Power Supply Calculator.
The calculator in the link above is great for a quick estimate, but what if you want to be able to run a more detailed calculation before purchasing your new PSU? The eXtreme PSU calculator pulls from a very detailed database of parts to give you a more accurate estimate. During our testing we were able to select the exact CPU and graphics card, for example, that our test system was running.
There are dozens of variables you can set within the Lite version of the calculator, for even more options there is a $US1.99 premium version of the calculator with even more settings for your calculating pleasure. Thanks Erik!