how long till 1800?

I'm 17 and rated 1370. I take chess seriously and would like to know when I can get to 1800+ and if you have any tips how to play better please do comment.

Buy a chess book with lot of commented master games - an history of chess for example, then go through it. You have to replay the games on board and try to understand the ideas behind the moves, sothe  explanations need to be quite good - prefer authors who highlight strategical ideas.
You will learn a lot and enjoy learning.

Then you have to learn tactics : a book could be useful here, it need two parts, one with descriptions of every kind of tactics, and one with exercises. 

books you recommend please?

que sera. sera

come on.be serious

took me 16 years  playing and studying off and on.  But I'm a weird case probably.  I'd say two years if you study tactics/master games seriously and play better opponents on at least a weekly basis.