PSU calculators confusing. Please help

kamikaze0808

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Oct 22, 2010
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I have just purchased some new components to revamp and older machine. As I got the parts in, I realized I forgot to consider power like the scrub I am. I have used a few different calculators and I'm getting drastically different results from 480w to 1200w

So here's the build

Asus Z97-A

Intel i7 Devils canyon

GeForce GTX 960

G skill 8gb x 2 ddr3 2400

Samsung 840 EVO SSD

Seagate 7200 HDD

Blu ray

the PSU I have is an Antec 650w which is 5 years old.

So my question is do I need to purchase a new PSU? If so which one? Or will my old one work with the new build?

Any help is appreciated.
Thank you.