I need a new PSU, but I'm very confused about how much power I need

First off all here are my specs

Motherboard: Asus P8Z68-V LX

CPU: i7-2600K LGA 1155

Ram: 2x 8Gigs DDR3 + 2x 4Gigs DDR3 = so 24 Gigs of Ram

GPU: GTX 970 (this is a recent upgrade for me.)

PSU: 700 Watts - XtreameGear SLI/CrossFireX Ready Power Supply ( I think I choose poorly one I got this PSU back in 2011)

HDD: One 2 TB 7200RPM

So I when I play new games like AC Unity, Batman Arkham Origins, TR 2013 with direct x 11 features and MSAA+ My PC will BOSD or freeze up. When I don't use heavy duty filters I am okay. So I determined that the problem must be my PSU.

I went to new egg looking for 850 Watt PSU and was ready to buy it but then I used new eggs Power supply calculator and It recommended that I get a 1179 watt PSU??

I goggled around and it seemed to me that a 850 PSU would be good enough but I guess not. Is the New Egg calculator messed up. I don't think New Egg even sells a 1179 watt PSU.

Here's the screen shot

These are the 2 PSU I was looking at:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139011
or
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139098&ignorebbr=1

I'm leaning more towards the CORSAIR HX Series HX850 850W.

Can anyone offer me any insight on this, do I really need an insane PSU?

It's most likely your poor choice in PSU. For your PSU you don't want to skimp out at ALL. For most single GPU configuration systems you won't need more than a 500w PSU. but for your case I would recommend a 650w PSU the minimum being a 80 Plus Bronze. however i believe you can get a 650w PSU that is 80 Plus Gold for at most $100

Edit: Also that Calculator is WAAAAAAAAAY off.

You have a similar build to what I have and I am getting by on 500W. So 500-600W will suffice.

Okay thanks for your advice guys. Now I can buy my new PSU.

get this

http://www.newegg.com/Product/Product.aspx?Item=N82E16817438018&cm_re=evga_psu-_-17-438-018-_-Product

thanks i ended up going for this one
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139011