The term "software engineer" is somewhat fuzzy (in Texas, for example, you have to have a 4-year engineering degree to legally call yourself an engineer). So just to clarify, I will answer for someone who is able to get a developer job.
There are a lot of aspects to getting a developer job that go beyond coding: your ability to interview well, to network effectively, and soft skills. Do people like you? Are they convinced that you're reliable?
Assuming you have those skills, I think that most people will be able to successfully get a developer job after 2,000 or 3,000 hours of deliberate practice building projects. So that's about 40 - 60 hours a week of coding. This will vary wildly - some people get a job after just a few months - but I think this is a reasonable conservative figure.