Frequently asked questions.
Short, sourced answers on mapping ZIP codes to city, county, FIPS, and coordinates — with the exact column names, from lists compiled from U.S. Census, HUD, and Interior data.
ZIP codes, cities, coordinates, and FIPS — quick answers
Short, exact answers to the questions people ask before they download a location List. Each one names the columns you get and links to the tool or List that answers it in bulk.
Read the FAQ → Q&AHow to calculate rent burden for a county: quick answers
Rent burden is median_gross_rent × 12 ÷ median_household_income. The ×12 matters: rent is monthly, income is annual. Worked examples and coverage notes.
Read the FAQ → Q&AHow to calculate home price to income for a county: quick answers
Home price to income is median_home_value ÷ median_household_income. What the result means, why "years" is a reading and not a unit, and a worked example.
Read the FAQ → Q&ASales territory data — quick answers
What this data can and cannot size for sales territories, and why.
Read the FAQ →Still deciding? Start with the free Basic City List — every U.S. city with its FIPS keys.
Download the free list