How long will it take to improve at chess

I have known how to play chess since childhood, played several games uptil now but I've started taking chess seriously since the past 4-5 days.

Initially, after about 15 matches, by elo was at 1350.

Then as I began to practice, like watching and analysing a couple of GM games, practicing tactics and playing games, it somehow went down to 1200,  which is contradictory. (and extremely frustrating)

I've practiced over 150 tactics in the past 2 days and raised my tactics rating from about 800 to 1100 today itself.

In great hope I went on to play a few games to test out my "new" abilities and lost 2 games consecutively (against 1280 and 1440)

I screwed up both games by committing silly blunders.

Any advice on how long it may take me to increase my ELO to 1500? 

Is there anything wrong with my current plan of preparation?

hard to say. it's just going to take time. keep doing tactics, studying games and nothing beats playing real games. chess is tough though. you will have your ups and many downs. 

        There is no contradictuion here. Remember this,the more experience and knowledge you gain in any endeavor ,the more you have to think about. Thus providing more opportunities to screw-up. You are a better player now then when you began,although yourrating may not reflect it now ,if you perservere,you will be rewarded for  your efforts.     GL

Your rating is not how good you are, it's how your games end. Over time and after many games your rating will be close to correct, but day to day it will fluctuate up and down even if you are learning.

Also it takes longer than 2 days to get a lot better. Don't pay attention to your rating, enjoy playing and learning, and check again after a month at the earliest.

@Ishanchoudhary

A lot of D class players actually experience loss in rating after reading GM games etc. (but this loss is only temporary) and I can offer the following two reasons:

1) You get inspired by the GM play and try to create a position like that, ignoring the realities of the board. Thus, you oversee tactics and instead try to get into particular positions. But before you studied the GM matches, you were on your own so you were more watchful

2) When you play in a textbook style, even though your position is improved - you enter positions that are wellstudied. So since your opponent is familiar with the terrain and it is possible that he will play better than you. But unconventional play at low levels is going to be harder to counter.

This doesn't mean you shouldn't study GM games.

But as a person who started out chess seriously earlier this year, I can advise that your best bet is to solve tactics. The best way to solve tactics is not to do it from a random website like chesstempo.

Just take any tactics book and solve all tactics of a theme. Then repeat the chapter, 10 more times. After this study a new chapter, then repeat this chapter 10 more times. After this, do both chapter 1 - all puzzles one/two times. Then move to chapter 3 etc. Finish the whole book, then solve the book again cover to cover once. Then you should be able to do any random puzzle from the book in 10 secs or under. Then study a basic opening system, and simply develop your pieces. You will easily get to your goal.

This was the actual study plan that I used: http://www.gautamnarula.com/how-to-get-good-at-chess-fast/

It takes time. just keep practicing and love what you're playing.

Improvement takes time...how much?  Who knows?  You will need to be able to deal with the highs and lows of the game.  Progress comes with a price.  What "progress" are you referring to?

"Every now and then someone advances the idea that one may gain success in chess by using shortcuts. 'Chess is 99% tactics' - proclaims one expert, suggesting that strategic understanding is overrated; 'Improvement in chess is all about opening knowledge' - declares another. A third self-appointed authority asserts that a thorough knowledge of endings is the key to becoming a master; while his expert-friend is puzzled by the mere thought that a player can achieve anything at all without championing pawn structures.

To me, such statements seem futile. You can't hope to gain mastery of any subject by specializing in only parts of it. A complete player must master a complete game ..." - FM Amatzia Avni (2008)

Here is a guess at the sort of book that might help:

Simple Attacking Plans by Fred Wilson

https://web.archive.org/web/20140708090402/http://www.chesscafe.com/text/review874.pdf

Logical Chess: Move by Move by Irving Chernev

https://web.archive.org/web/20140708104437/http://www.chesscafe.com/text/logichess.pdf

The Most Instructive Games of Chess Ever Played by Irving Chernev

https://chessbookreviews.wordpress.com/tag/most-instructive-games-of-chess-ever-played/

Winning Chess by Irving Chernev and Fred Reinfeld

https://web.archive.org/web/20140708093415/http://www.chesscafe.com/text/review919.pdf

Discovering Chess Openings by GM John Emms

https://web.archive.org/web/20140627114655/http://www.chesscafe.com/text/hansen91.pdf

Openings for Amateurs by Pete Tamburro

http://kenilworthian.blogspot.com/2014/05/review-of-pete-tamburros-openings-for.html

Chess Endgames for Kids by Karsten Müller

https://chessbookreviews.wordpress.com/tag/chess-endgames-for-kids/

Everyone is different some people improve in six months to a year and make rapid progress others take longer one thing I know for sure is if you have patience and train/study chess systematically the right way ( you are on site with everything you need and 1st class trainers) you'll be a much better player in the long run than that guy who isn't doing what it takes and is just spinning in his hamster wheel playing 5.0 all day and the parham attack 1.e4 e5 2.Qh5

Rushing things treating chess like a race isn't the way to go! You want to be a solid player or the guy in the hamaster wheel decide?!

Good luck.

2 examples of people i know

1 guy studies nothing but tactics.  He is consistently rated around 2000 USCF.  He is constantly rated between 1900-2050 and doesnt understand why?  He is a tactical monster, but continuously get outplayed by people that have a good all around game.

1 guy studies evertything.  He made Master and quit chess.  

Analyze your games and learn from your mistakes. That's how you'd learn and improve in anything else in life and it should definitely apply here too

Depends on the way you do it, and on the person. I stand for the same as post #13.

If you get frustrated after losing few games in a row you will start playing way worse then you normally do. I guess that can be the reason for your rating decline.