Im not really sure how you calculate the wattage , so i turned to this website for help. Here is my build:
Case:Gigabyte GZ-G2 Gaming Case Plus with USB 3.0 Ports & 2 Front Fans (2x120 front fans and 1x120 fan on top)
Motherboard:Gigabyte B75M-D3V S1155 Intel B75 DDR3 mATX
RAM:Kingston 8GB (2 x 4GB) HyperX Blu DDR3 1600MHz DIMM 240-pin CL9
HDD:Seagate 2TB Barracuda SATA 6Gb/s 64MB 7200RPM Hard Drive
CPU:Intel Core i5-3570 S1155 3.4GHz 6MB
GPU:GeForce GTX 560Ti 900MHz 1GB
Also I went over several calculator sites, but the results differed. Thanks in advance
The wattage would be ok, but that's a piss poor quality unit. Only 34A (408W) max on the 12V rail. For a supposedly 600W unit, that's terrible.
Some good advice that you should absolutely follow: DON'T cheap out on the PSU! It's THE most important part of your system and quality definitely matters. Yes, quality costs more, but it's absolutely worth it. You don't want a bad PSU failing catastrophically and taking all of your other components with it.
Now, any 500-550W unit from SeaSonic, Corsair, Silverstone, Antec, PC Power & Cooling, and XFX (also a few from OCZ) would be just fine and is what I would recommend.