Housing costs are based on the Department of Housing and Urban Development’s fair market rents, which represent rental costs (shelter rent plus utilities) at the 40th percentile in a given area for privately owned, structurally safe, and sanitary rental housing of a modest nature with suitable amenities. Studio apartments were used for one-adult families, one-bedroom apartments for two-adult families, two-bedroom apartments for families with one or two children, and three-bedroom apartments for families with three or four children.

Food costs are based on the U.S. Department of Agriculture’s national “low-cost” food plan and adjusted to each area using multipliers from Feeding America’s Map the Meal Gap data. The low-cost plan is the second-least-expensive of the four Official USDA Food Plans and assumes almost all food is bought at the grocery store and then prepared at home. The USDA food plans represent the amount families need to spend to achieve nutritionally adequate diets.

Child care expenses are based on costs of center-based child care and family-based care for 4-year-olds and school-age children, as reported by the Child Care Aware of America. We assume all families in urban areas use center-based care and all families in rural areas use family-based care. For one-child families, we assume the child is 4 years old. For families with more than one child, we assume the additional children are ages 8, 12, and 16, respectively.

Transportation expenses are a combination of the costs of auto ownership, auto use, and transit use. Transportation cost data were provided by the Center for Neighborhood Technology (CNT). CNT created a modified version of transportation costs from its Housing and Transportation Affordability Index to account for differences in family types in the Family Budget Calculator.

Health care expenses include insurance premiums and out-of-pocket costs, and assume families purchase the lowest cost bronze plans on the health insurance exchange established under the Affordable Care Act. Data on premiums come from the Kaiser Family Foundation and the U.S. Department of Health and Human Services (HHS). Out-of-pocket medical costs are calculated from HHS’s Medical Expenditure Panel Survey.

Other necessities include apparel, personal care, household supplies (which include items ranging from furnishings to cleaning supplies to phone service), reading materials, and school supplies. The costs for these items come from the Bureau of Labor Statistics Consumer Expenditure Survey, and use data reported for households in the second (from the bottom) fifth of households in the household income distribution.

Taxes are calculated from the National Bureau of Economic Research’s Internet TAXSIM, an online tool that calculates information on federal personal income taxes, state income taxes, and federal Social Security and Medicare payroll taxes.