well the focus of my question was to know if for instance i say i have in my account 50k or 100k and i am able to say i can dedicate my life to day trading. or i need an account of 1M to start thinking that?
its a very difficult to answer as it depends on your personal circumstances. I'll give you some advice based on me making some assumptions about you and your bankroll.
NVP was trying to say don't give up your day job. Try trading part time and at least that way if you do make the mistake in choosing this path as your career you will still have your job to fall back on. If you didn't inherit your money you are doing well enough in your current job to have saved enough money to consider jacking it all in so we would all like to emphasise to you that you must really consider whether walking away from your salaried job is the right thing to do. (its not btw)
That said and assuming you still want to go ahead and trade for a living you shouldn't target more than 3% per month return on your investment.
You then need to decide whether you roll your profits so the 3% compounds each month or whether that is money you need to live on and you will have to withdraw it each month.
If you have to withdraw it each month your slippery slope just got a lot more slippery.
Lets assume you put £20,000 in to a trading account and you make 3%. At the end of the first month do you withdraw the £600 or let it roll and start month 2 with £20,600?
If you withdraw it is £600 enough? if you need £2,000 per month for example then I would suggest your pot size needs to be at least £60,000.
What happens if you withdraw the £600 and in month 2 you lose £1,000 and in month 3 you also lose £1,000. Now you've only earned £600 in a 3 month period and your pot is now only £18,000. If you make 3% in month 4 then you've only made back £540. not much is it.
Alternatively you can roll the dice and use high leverage and scalp and overtrade and do all the things most over awful retail traders do and lose all of it in a matter of weeks.
this is what you should do:
1. keep your job
2. open a live trading account with a good spreadbet company
3. deposit £500
4. trade your strategy and see how you get on. Do not focus on doubling your money but try and make steady returns each day
5. close your account, forget the £500 you've just lost and concentrate on your job again.
6. repeat 1-5 until the penny drops that this isn't an easy route to riches.
I don't mean to be sarcastic but I do hope you realise that any experienced trader will tell you that it is more likely you will lose your money than make money trading. Listen to that advice.