It really depends. If you take the MBA track, it would likely be 4-5 years of pre-MBA experience, 2 years to get the degree, and then maybe a year or two post-MBA depending on the firm and the person involved – call it 30.
There are other places where you can get in as a junior analyst right from undergrad or after a couple of years of banking or research somewhere else and then move up very quickly.
I’ve also seen people who started learning to invest at age 12 and then went to Wharton (or whatever) do it straight out of school.
The truth is you can only work from where you are at today, and that you will only make yourself miserable if you compare yourself to others. Do what you enjoy, and do it as well as you can, and you shouldn’t have any regrets in life.
I don’t think you are too old at all. The firm I work for targets 25 to 35 for incoming analysts.