Methodology

1. Geography: ZIP codes vs. ZCTAs

A ZIP code is a USPS mail-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 Houston ZIPs the two match closely. They diverge for post-office-box ZIPs, single-building ZIPs (large office towers, the Medical Center campus) and ZIPs whose delivery routes cross a ZCTA boundary. Where the ACS reports no resident population for a ZCTA we do not publish a profile, which is why a handful of Houston ZIP codes that exist for mail purposes do not appear here. The 163 ZIPs we cover span Harris County and the parts of Fort Bend, Montgomery, Brazoria, Galveston, Waller and Chambers counties that function as part of the Houston metro.

2. Primary source: ACS 2020–2024 5-Year Estimates

Population, age, household size, race and Hispanic origin, household and per-capita income, median home value, median gross rent, tenure (owner vs. renter), housing units and vacancy, educational attainment, and journey-to-work (commute time and mode, including work from home) all come from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates, retrieved from data.census.gov at the ZCTA level. We use the 5-year product rather than the 1-year product because the 1-year estimates are not published for geographies under 65,000 people, which excludes almost every ZIP code. The trade-off is that a 5-year estimate describes the average condition across the whole 2020–2024 window, not a single point in time; a ZIP that changed rapidly in 2023–2024 will read as slightly older than it is.

Each field maps to the corresponding ACS detailed table for the ZCTA — for example B19013 for median household income, B25077 for median home value, B25064 for median gross rent, B25003 for tenure, B15003 for educational attainment (population 25 and over) and B08301/B08303 for commute mode and travel time — so any figure on a ZIP page can be looked up directly on data.census.gov by table and ZCTA.

3. Derived figures we compute ourselves

• Price-to-income ratio = median home value ÷ median household income. We treat 3.0 as the attainability benchmark, the long-run U.S. norm below which a household earning the local median can generally buy the local median home with a conventional mortgage.
• Rent-to-income ratio = (median gross rent × 12) ÷ median household income, expressed as a percentage. Above 30% is "cost-burdened" under the U.S. Department of Housing and Urban Development definition. Both ratios use ZIP-level medians, so they describe the area, not any individual household.
• Diversity index = the probability, on a 0–100 scale, that two residents chosen at random belong to different race/ethnicity groups (the Simpson diversity index applied to the ACS B03002 categories: non-Hispanic white, Hispanic, non-Hispanic Black, non-Hispanic Asian, other).
• Metro benchmarks shown on ZIP pages ("above the Houston average") are medians across the 163 ZIP codes with each ZIP weighted equally, not population-weighted. This makes small affluent ZIPs and large working-class ZIPs count the same; population-weighted figures would sit closer to Harris County's values.
• Rankings sort ZIPs on a single ACS field. Ties are broken by ZIP number. We do not publish composite "livability" scores that blend metrics with hidden weights; where a page filters ZIPs on several conditions at once (as in the 2026 affordability report), the exact conditions are stated on the page.

4. Flood risk, climate and geography

Each ZIP's flood tier (High, Moderate, Low) reflects the predominant FEMA flood-zone designation across its area from the National Flood Hazard Layer: zones A and AE (the 1%-annual-chance Special Flood Hazard Area, where flood insurance is required on federally backed mortgages) are rated High; zone X500 (0.2%-annual-chance) Moderate; unshaded zone X Low. Historical flood-event counts are compiled from public records of major flood events that affected the ZIP. A ZIP-level tier is a summary: individual parcels inside a Moderate ZIP can sit in an AE zone and vice versa, and readers evaluating a specific address should use the FEMA Flood Map Service Center. Hurricane evacuation zones follow the Harris County zip-zone system. Elevation, land area and coordinates come from public geographic datasets for the ZCTA; temperature and rainfall figures are NOAA climate normals for the Houston area.

5. Schools, amenities and neighborhood names

School listings pair each ZIP with public schools serving it, compiled from public school-district directories and rating sources and shown on a 1–10 scale. Amenity counts (restaurants, parks, grocery stores, hospitals, pharmacies, gyms) are point-of-interest counts within the ZIP area from public mapping data and should be read as order-of-magnitude indicators, not inventories. Neighborhood names attached to each ZIP are the commonly used names for the communities inside it, based on local usage and the City of Houston's super-neighborhood map; they are editorial, not official ZIP attributes.

6. Editorial content

The neighborhood profile, affordability assessment and livability summary on each ZIP page are written by the Houston Zip Codes Data Team from that ZIP's specific data signature, and the blog articles, neighborhood guides and reports are researched and written by the same team. We do not accept sponsored rankings, paid placements or real-estate referral fees, and no page's content is influenced by advertisers. Where we characterize an area (affordable, flood-prone, family-oriented) the description is derived from the figures on the page, and the figures are always shown so readers can disagree with the characterization.

7. Known limitations

• ACS estimates carry margins of error that grow as population shrinks. For ZIPs under roughly 5,000 residents, income and home-value estimates can have margins of ±15–25%; differences of a few percent between two such ZIPs are not meaningful.
• Median home value is the owner's estimate of what the home would sell for, from the ACS questionnaire, not a transaction price or an appraisal. It lags the market in fast-changing ZIPs.
• Median gross rent includes utilities and covers all occupied rental units, including long-tenured leases, so it runs below current asking rents.
• Crime statistics are not published on this site. The ACS does not collect them, and ZIP-level crime rates from police data are not comparable across jurisdictions. The crime fields in our dataset are intentionally zero.
• Commute figures for two ZIPs (77046 Greenway Plaza and 77050) are suppressed in the ACS and shown as unavailable.

8. Update schedule

The Census Bureau releases new ACS 5-Year Estimates each December. We rebuild the full dataset after each release (the current dataset is the 2020–2024 vintage, released December 2025), re-run every derived figure and ranking, and re-review the editorial text on pages whose numbers moved materially. Flood tiers are checked against the National Flood Hazard Layer at the same time. Between annual rebuilds, corrections are applied as they are found.

9. Corrections and contact

If a figure on this site does not match its Census source, or a neighborhood name, school or flood designation is wrong, tell us through the contact page 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. The complete ZIP-level dataset is available for download as a spreadsheet (houston-zip-codes-census-data.xlsx) so anyone can check our arithmetic.