The average time for a blackbelt in BJJ is 8-10 years depending upon the place where you train and their opinion on training standards and methods.
I would never give any student a black belt in less than 8 years no matter how good they were. In fact the average time for me to consider it would be 10 years + in GJJ but in BJJ maybe 8 years.
It has nothing to do with how much you train each week, it has more to do with the quality of your training and understanding of curriculum.
1000-2000 hours out of 10,000 hours for mastery, is usually what the First degree or dan black belt is awarded at, although the original standard was "proficiency" with a number of life or death techniques and situations. Means they got more than a 50/50 chance of surviving.
4x12 would be the number of weeks in a year. Usually people take about 1-3 years, if not more, to get the time.
As Shae said, 8-10 years is the average. I wouldn't get caught up with belts, because you're likely going to walk away disappointed. Belts are not handed out like candy, like in other styles. You have to have a competence in the art, and demonstrate that against other resisting opponents. This takes time to learn, and how often you go doesn't necessarily mean you'll learn it faster or advance faster in the ranking system.
As long as you want.
I'm 31 and plan to train 4 times a week how long would it take for me to get to brown and then to my black belt training this many times a week ?
