What watt psu will be needed for this?

[KyleRaino]

I am getting a pc off of a friend that is coming with an Intel i3 2120 and I plan to add a gpu (evga gtx 1050ti, mainly because I don't need a pcie power lead) upgrade ram to 16gb ddr3 hyperx fury ram, I don't know the psu yet, but what watt psu will be needed? As Ive never upgraded a psu before, and don't really know how to/want to but I can't imagine it will be a great psu, coming from an old desktop

 

[henry28]

all you need is 550watts but i like to get 650w just to open areas for upgrading