How much power do I need?

[FliSh101]

I have used a lot of power supply calculators but the recommended power are all different some say 700 some 800 and some 1000. what is the best psu calculator and how much power do i need for this build?
http://uk.pcpartpicker.com/list/twFgLD

 

[Bearmann]

You need 850W. Each card takes a 75W plus a 150W PCIe cable plus 75W from the MB. So that 600W for the GPU's plus the CPU and assorted minor extras like fans, etc. You would do fine with a quality 850W or 1000W unit.