Help to choose between 850va and 1200va UPS (Uninterruptible Power Supply)

[ROHAN-SNAKE]

Hello. Sorry for my English. I live in Mauritius Island and I want to buy a UPS for my computer because there is so much power cut in my region which is bad for my PC. I wanted to buy some good brand UPS on Amazon but the import fees and shipping is way too much. So, I went to a local store and there were some UPS with unknown brands (I'm not sure if it is some Chinese UPS) but I need it and I have to stick with it.

So they had PowerTree 850va and 1200va and I have to choose between these two.

I don't know which one to choose. I want to buy 850va because of my low budget but I'm not sure if it will be good for my system.

Specs:

OS: Windows 10 Pro 64bit
MB: MSI B150M MORTAR
CPU: Intel Core i7- 6700
RAM: Crucial Ballistix Sports LT 2 x 8GB
GPU: MSI AERO GTX 1070 8GB OC
SSD: 2 X 240 GB
HDD: 2 X 2 TB
PSU: EVGA SuperNova 550 G2 (80+ Gold)
PERIPHERALS: 1 USB Keyboard, 1 USB Mouse, 1 Xbox 360 Wireless Receiver

I've read a post where it says [1.6*My PSU watt (550w) = 880va] then based on the 880va you must choose your UPS. However, a 550w does not always use 550w, it can use 400w or below. So there is no matter in picking a UPS below 880va. They say it will work fine.

But you know I want to be really 100% sure before buying. Please tell me which is best for my specs.

 

[_Cosmin_]

880VA should suffice if you don`t plan to keep it working long time without main power. However make sure they are "Line Interactive" or "Double Conversion" models for best protection.