Well, I think that it depends of how much effort you put into it. Learning any language requires a big amount of time and dedication, in order to be fluent in it and feeling comfortable while speaking it. But, if you dedicate at least 2 to 3 hours of your day to pratice the language you´re learning, you can be capable of speaking it fluently even in half a year. It´s all about dedication.

It depends entirely on how much effort you're prepared to make.

*How much time does it take to be fluent in English?

I agree with other colleagues, it depends of how much effort you put into it. My goal is to be fluent in English in a year. I've been studying for 7 month, about 2 hours a day. I feel very comfortable talking with natives, but I need to improve grammar, pronunciation, vocabulary and comprehension (I understand almost all I hear, but sometimes when I watch some movies it's hard to understand somethings.