Lets put it this way. What passive income (pre tax) makes you comfortable, if you were to put all your current net worth ( Which excludes the house you live in) in a very low risk instrument, say a 10 year government bond?. Keeping in mind, 1. The retained earnings are large enough and it will be redeployed. Hence will keep compounding. 2. Occasionally, you may have to dip into the investment for one offs.
I know there is no right answer for this question as well, since it depends on the individual. But is 360k USD per year considered decent? I know it depends on the city. But I have used a normalised number of 360k to keep it simple. (Actually I have used 1 crore per year (10 million INR) Indian rupees in this example. Converting it to USD based on the purchasing power)