Methodology

1. Geography: ZIP codes vs. ZCTAs

A ZIP code is a USPS delivery route, not a geographic area, and the Census Bureau does not publish statistics for it directly. Every demographic figure on this site is reported for the corresponding ZIP Code Tabulation Area (ZCTA), the Census Bureau's approximation of a ZIP code built from whole census blocks. For most residential ZIPs the two match closely; they diverge for post-office-box, single-building (the Woolworth Building, 10279), airport (JFK, 11430) and park or military ZIPs (Fort Totten, 11359). Each borough is coterminous with one county (Manhattan = New York County, Brooklyn = Kings, Queens = Queens, the Bronx = Bronx, Staten Island = Richmond), so county pages and borough pages describe the same ZIPs.

2. ZIPs without demographics

5 of the 183 ZIPs in this directory have no usable housing data: 3 are PO Box or unique ZIPs (they serve post office boxes, a single building or an institution rather than a residential delivery area), and two standard ZIPs report no owner-occupied home value (11359 Fort Totten, 10037 in Harlem, where nearly all housing is rental or public). Where the Census publishes its "not available" code, the dataset stores the field as missing; those pages say so instead of showing zeros, point to the nearest delivery ZIPs that do carry data, and are excluded from every median, rank and report. That leaves 178 ZIPs with full housing data, which is the population every "of 178" rank on this site refers to.

3. Primary source: ACS 5-Year Estimates

Population, density, median age, sex ratio, median household income, per-capita income, median home value, median gross rent, owner- and renter-occupancy, total housing units, high-school and bachelor's attainment (population 25 and over), poverty rate, unemployment, and land and water area come from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates, retrieved from data.census.gov at the ZCTA level. The 5-year product is used because 1-year estimates are only published for geographies of 65,000 or more people, which excludes almost every ZIP. A 5-year estimate describes the average condition across the collection window rather than a single point in time. Each field maps to a standard ACS detailed table — B01003 for population, B19013 for median household income, B19301 for per-capita income, B25077 for median home value, B25064 for median gross rent, B25003 for tenure, B17001 for poverty, B15003 for educational attainment, B23025 for employment status and B01002 for median age — so any figure can be checked directly on data.census.gov by table and ZCTA.

4. The $2,000,001 and $250,001 caps

The ACS top-codes median home value at $2,000,001 and median household income at $250,001. 4 New York City ZIPs sit at the home-value cap (Tribeca 10007 and 10013, Lincoln Square 10069 and Battery Park City 10282) and 4 at the income cap (10004, 10007 and 10282 in Lower Manhattan). Their true medians are higher, so any ratio computed from a capped value is a floor. Our reports and per-ZIP profiles mark these with "at least" or a plus sign; ZIP pages show the capped value as the Census reports it.

5. Figures we compute ourselves

• Price-to-income ratio = median home value ÷ median household income. 3.0 is the long-run U.S. norm; ratios above 5.0 are conventionally described as severely unaffordable. The median New York City ZIP is currently 8.7; the city's ratios are inflated by the fact that ACS home value covers only owner-occupied units, which in much of Manhattan means condominiums and co-ops rather than houses.
• Rent-to-income ratio = (median gross rent × 12) ÷ median household income, as a percentage. Above 30% is "cost-burdened" and above 50% "severely cost-burdened" under the U.S. Department of Housing and Urban Development definitions. Both ratios use ZIP-level medians and describe the area, not any individual household.
• Citywide and borough benchmarks are medians across the ZIPs in scope with each ZIP weighted equally, not population-weighted. Borough and county populations are the sum of their ZIPs' ACS populations.
• Ranks ("N of 178") sort every ZIP with housing data on a single ACS field, 1 = highest. Borough affordability ranks sort the borough's ZIPs on price-to-income, 1 = lowest ratio.
• Nearby ZIPs are the closest entries in the dataset by straight-line distance between ZIP centroids.
• Density bands in the written profiles (high-rise, classic apartment, row-house, detached-house belt, low-density) are fixed thresholds on residents per square mile: 90,000, 50,000, 20,000 and 8,000, set for New York rather than national norms.

6. Editorial content

The description, FAQs and "Affordability & Profile" section on each ZIP page, the "at a glance" overview on each borough and county page, and every report are generated by the NYC Zip Codes Data Team from that area's specific figures and reviewed before publication; each sentence is conditional on the numbers, so two areas with different data read differently. We do not accept sponsored rankings, paid placements or real-estate referral fees, and no page's content is influenced by advertisers. Crime, school and walkability scores are not published on this site: the ACS does not collect them, and ZIP-level versions from third parties are not comparable across the five boroughs.

7. Known limitations

• ACS estimates are survey-based with margins of error that grow as population shrinks. Small Lower Manhattan ZIPs (10004, 10005, 10006) and institutional ZIPs carry wide margins; small differences between such ZIPs are not meaningful, and reports restrict rankings to ZIPs above a stated population floor.
• Median home value is the owner's estimate from the ACS questionnaire for owner-occupied units only, not a transaction price, and is capped at $2,000,001. In co-op-heavy ZIPs (Co-op City 10475, Parkchester, parts of Queens) it reflects share prices and can be far below the price of a house on the same block.
• Median gross rent includes utilities and covers all occupied rental units, including long-tenured and rent-controlled leases, so it runs well below current asking rents in New York; rent-stabilized and public housing pull ZIP medians down further.
• ZIPs dominated by students (Morningside Heights 10027, NYU), by public housing, or by a single institution show medians that describe residents, not the buyer or renter pool.
• The borough name is used as the USPS city for every ZIP; neighborhood names (Astoria, Flatbush, Riverdale) are not part of the dataset.
• ZIP-level medians describe areas, not households.

8. Update schedule

The Census Bureau releases new ACS 5-Year Estimates each December. We rebuild the dataset after each release, re-run every derived figure, profile and report, and re-review pages whose numbers moved materially. Between annual rebuilds, corrections are applied as they are found.

9. Corrections

If a figure on this site does not match its Census source, or a city or county assignment, ZIP type, nearby-ZIP list or description is wrong, tell us with the ZIP code and the field in question. We verify against the primary source and correct the page; substantive corrections are noted on the affected page and on the About page.