There are some simple guidelines for BRM
Pot limit and no limit Hold'em.
If you are playing pot limit or no limit poker, the safe recommended size of your bankroll is 20 times the full buy-in of where you want to play. This means that if you want to have the best chance of making money at a $1/$2 game where the maximum buy-in is $200, you should have a bankroll of at least $4000.
Another way of applying bankroll management is by only putting a maximum 5% of your entire bankroll on the table at any one time, which works out the same as having 20 times the buy-in for the game.
If you like to play limit Holdem however, you should have 300 Big Bets as a minimum for the limit you wish to play at. Therefore to play $1/$2 limit Holdem, you should have a bankroll of at least $600.
It is recommended that you have a bankroll that will give you 40 buy-ins to the level of tournaments that you wish to play at. Therefore if you want to play at the $10+$1 Sit n Go's you should have a bankroll of $440.
But even with a BRM u can lose ur whole BR if ur skills are not good enough or the poker gods are against u ( variance)
GL at the tables