I haven't found this in the forums here, but this looks like an interesting tool. On this site, you select how many sockets you have, what chip you are using, CPU utilization, video card model, HDD type and how many, number of ram sticks, what number and how many types of fans, water cooling models, system load and estimate a capacitor aging rate. There is a wide range of variables to enter.
Antec Power Supply Calculator
Antec Power Supply Calculator