If you carry a credit card balance, the minimum payment is a "need" and it counts toward the 50 percent. Anything extra is an additional debt repayment, which goes toward this 20 percent category. If you carry a mortgage or a car loan, the minimum payment is a "need" and any extra payments count toward "savings and debt repayment."
Next list all your variable expenses_those that may change from month to month such as groceries, gas and entertainment. This is an area where you might find opportunities to cut back. Credit card and bank statements are a good place to start since they often itemize or categorize your monthly expenditures. Tip: Record your daily spending with anything that’s handy_a pen and paper, an app or your smartphone.