Ten years ago, in an earlier Gallup poll, the average American believed a household could get by on $58,000 a year. The Gallup figure from 2013, $58,000, was about 10 percent higher than the median household income for that year. That report, derived from MIT’s Living Wage Calculator, assumes the average family will allocate half of its after-tax income to basic living expenses, 30 percent to discretionary spending and 20 percent to savings and debts.