21, wanting to start saving/investing now. I always hear people say, "you should have X saved by the time you're 40". What should I aim for?

A super loaded and somewhat ambiguous question I know, I just didn't know how to word it that well.

Basically, I'm still in school, but have enough expendable income to start saving/putting money in a long term investment account. I always hear people say to shoot for X saved by your X birthday, but wasn't really sure what goals I should set.

Submitted January 31, 2017 at 11:08AM by VerifiedCrazyPerson http://ift.tt/2jzazYR