You do not have to be a billionaire to consider yourself to be financially successful. If you have a roof over your head, food on your plate, loving family and friends, you are already in a good class.
Financial metrics have some limitations. For example, debt-to-income will be different for people of different ages. For those who have unpredictable income, ratios may be difficult to assess without normalizing for volatility.
Monetary assets are liquid investments. The average household can include cash, money markets, savings, and checking accounts.
Liquidity Ratio = Monetary Assets/ Monthly Expenses