Why Confidence Level 95% is -1.65? I'm learning about Value at Risk for Investing which got me into statistical questions.
Here it's said that
For a confidence level of 95%, # of Standard Deviations (σ) = -1.65 x σ
And for a confidence level of 99%, # of Standard Deviations (σ) = -2.33 x σ
My question is, where do we get the -1.65 from? I've googled and found that for investing, the 95% confidence level always uses -1.65 in here, here, and this youtube video.
However when from the answers on this post, you can see that people are sure that -1.65 belongs to a 90% confidence level. Also see this answer.
So which one is correct? And how does it get the number from anyway? (Sorry I did not learn about statistics, please share a source to learn if you have)

Tim is correct.  If you want to know how the 1.65 is calculated.
It is the inverse of the standard normal cumulative distribution.  You can use the excel formula normsinv to calculate it. 50% will give a value of zero.  The probability can be from 0 to 1, although these values return an error in excel.
