The amount will be different for each person based on their life style. Good way to measure is based on your current salary from your full time job.
What ever the annual salary you are living with currently times three must be saved up and put aside as emergency funds. This amount cannot be touched or used as
bankroll. This is the amount that you come back to if you fail as a poker player and need to get a new job again. You will have 3 years to get a job and get back on track.
I quit my job with that method but I am a sports bettor. I new to poker and trying it out. But i have a steady cash flow from my sports betting winnings each month. I find sports betting lot less stressful and less time consuming. I am trying poker as a hobby because its fun but i don't think i could ever play full time sitting on a table.