I gave a threshold to go off of in my most recent comment:This is one of the most unanswerable questions. I totally get where you are coming from, I wanted to know the same thing last year when I started. This Sunday marks my first year doing Youtube and I'm just past 20,000 subs. But that is not even close to normal. It has a lot to do with trends, the algo picking your videos, finding the right audience, luck, hard work, SEO..etc.
Based on my observation of a bunch of channels, if you work hard, you may get 1k at the end of the first year. But there are so many aspects to this that I would never tell someone to put their hopes in something like that. They may get 1k in 3 months or 3 years.
"Ok, here. Let me try a different approach to this. If you get your 100th subscriber within X amount of time of your channel actually uploading its first video, how long until you actually reach 1,000 subscribers, assuming you're using the same tactics regarding SEO, upload frequency, average length of episodes, and suchlike?
Would it be 3x time before reaching 1k? Maybe 5x?"