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."
List your expenses starting with the most important to the least important. Listing the expenses in order makes it easier to make cuts in your budget if needed. The most important should be things that cover your necessities. You will need to cover your housing, food, utilities (not including cable television), transportation costs, debt payments, and savings goals first. Then you will list luxury items which can include clothing, entertainment, eating out and gym memberships.