source the Tax Policy Center the Tax Policy Center Average federal income tax rate: would have paid source Historical Average Federal Tax Rates for All Households about a 20% rate 3 percent the average federal tax rate of 17.6% Tax Policy Center 3.8 percent since 2000 Tax Policy Historical Average Rates 1979 to 2013 Average Effective Tax Rate more useful Tax Policy Center Historical Average Federal Tax Rates for All Households 3.8 percent since 2000 Tax Policy Center most low-income workers pay Tax Policy Center the average federal tax rate of 17.6% source look at this