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."
Envelope Budget: An envelope budget is a budget where you assign money to each category and deal with cash for several of your expenses. You take the cash out for each month and put the money into different envelopes labeled for the category. When you run out of money in that category, you stop spending. This is a good strategy if you are not good at tracking your expenses. Most people still pay their bills online through their checking account. In order to make this work, you cannot use your debit card for the categories that you have envelopes for.