Methodology
How the 96 ZIP code profiles, city and county pages, and reports on this site are sourced, computed and checked. Census figures last refreshed and checked: October 31, 2026.
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 matching 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 PO box, single-building and industrial ZIPs.
The dataset has 96 ZIP codes: 61 with a Los Angeles mailing address and 35 in 26 surrounding cities across Los Angeles, Orange, Riverside, San Bernardino and Ventura counties. It is not every ZIP code in the region; the City of Los Angeles' San Fernando Valley ZIP codes, for example, are not in it yet. A Los Angeles mailing address is a USPS city name, not a city boundary: a few of those ZIPs are mostly unincorporated county land. Each ZIP is listed under one county.
2. Primary source: ACS 5-year estimates
Population, age, income, home value, rent, tenure, education, poverty and unemployment come from the U.S. Census Bureau's American Community Survey (ACS) 5-year estimates, vintage 2020-2024. The 5-year product is used because 1-year estimates are only published for areas of 65,000 people or more. A 5-year estimate describes the average condition across the five-year collection window rather than a single year.
The table below lists each field, the Census table it most likely comes from, and the variable to use when the data is refreshed. The original pull did not record table IDs, so these are the standard tables for each figure; every Census field is being re-pulled from them for the 2020-2024 release.
| Field | Source table | Variable | Status |
|---|---|---|---|
| Population | B01003 | B01003_001E | refresh locally |
| Median age | B01002 | B01002_001E | refresh locally |
| Male / female share | B01001 | B01001_002E and B01001_026E ÷ B01001_001E | refresh locally |
| Median household incomeA zero means the Census Bureau did not publish a median; the site shows it as not reported. | B19013 | B19013_001E | refresh locally |
| Per-capita income | B19301 | B19301_001E | refresh locally |
| Poverty rate | S1701 | S1701_C03_001E (or B17001_002E ÷ B17001_001E) | refresh locally |
| Unemployment rate | S2301 | S2301_C04_001E (or B23025_005E ÷ B23025_003E) | refresh locally |
| Owner / renter share of occupied homes | B25003 | B25003_002E and B25003_003E ÷ B25003_001E | refresh locally |
| Housing units | B25001 | B25001_001E | refresh locally |
| Median home value (owner estimate)Top-coded at $2,000,001. | B25077 | B25077_001E | refresh locally |
| Median gross rentTop-coded at $3,501 in recent releases. | B25064 | B25064_001E | refresh locally |
| High school graduate or higher (age 25+) | S1501 | S1501_C02_014E | refresh locally |
| Bachelor's degree or higher (age 25+) | S1501 | S1501_C02_015E | refresh locally |
| Mean travel time to workMinutes, workers 16 and over who did not work from home. | DP03 | DP03_0025E | refresh locally |
| ZIP center pointUsed for the map and for nearest-ZIP distances. | Census Gazetteer, ZCTA file | INTPTLAT / INTPTLONG | verify locally |
| Land and water areaSquare miles. | 2020 Census ZCTA geography (Gazetteer / TIGERweb) | ALAND_SQMI / AWATER_SQMI | verify locally |
| Population densityPeople per square mile of land. | Computed: population ÷ land area | B01003_001E ÷ ALAND_SQMI | computed |
| County | 2020 ZCTA-to-county relationship file | County with the largest share of the ZCTA's population | verify locally |
| USPS city and ZIP type | USPS ZIP Code Lookup | Preferred city name, ZIP classification | verify locally |
| Main area code | NANPA area code maps (not a Census figure) | Main code for the ZIP's area; overlay codes also apply | verify locally |
Table links open the table search on data.census.gov; choose the ZIP Code Tabulation Area and the 5-year release there. Status "refresh locally" means the field is re-pulled from that table on the owner's machine, which holds the Census API key.
3. Census caps and missing values
The ACS top-codes median home value at $2,000,001 and median gross rent at $3,501. ZIPs at either cap show "$2,000,000 or more" or "$3,500 or more", and any ratio built from a capped value is a minimum, marked with a plus sign. Where the Census Bureau does not publish a median (it reports a zero), the site shows "Not reported" rather than $0.
ZIPs with fewer than 1,000 residents or no published median income are profiled but left out of every rank and median. ZIPs with fewer than 5,000 residents carry a margin-of-error caution on their page.
4. Figures computed on this site
- Los Angeles ZIP median: Middle value across the City of Los Angeles ZIP codes on this site that have full data, each ZIP counted once (not population-weighted).
- Rank: Position among all ZIP codes on the site with full data, highest first. Ties share a rank.
- Price-to-income ratio: Median home value ÷ median household income. Demographia rates 3.0 or less as affordable and above 5.0 as severely unaffordable.
- Rent-to-income share: Median gross rent × 12 ÷ median household income. HUD treats more than 30% as cost-burdened and more than 50% as severely cost-burdened.
- Income multiple: Median household income ÷ per-capita income. Higher values usually mean more people, and often more earners, per household.
- Nearest ZIPs: The five closest ZIPs on the site by straight-line distance between ZIP center points.
- Similar profile: ZIPs with the smallest combined difference on income, home value, rent, age, ownership, degree rate and poverty, after scaling each to its spread across the site.
5. How the page text is written
The analysis on ZIP, city and county pages is generated by code from the figures above, not written by hand for each page. For each ZIP, the code finds the figures where it sits furthest from the middle of the site (top or bottom fifth), picks at most one per topic, and describes them along with the related figures that explain them. The neighbor comparison names the figure on which the ZIP differs most from its five nearest ZIPs and the nearby ZIP least like it. "Income ahead of or behind education" compares a ZIP's median household income with a straight-line fit of income on bachelor's-degree rate across all ZIPs on the site. The FAQ answers on each page are built from the same record. Because every sentence is chosen by the numbers, a page changes when its data changes.
6. Land area and density
Land and water area come from the Census Bureau's 2020 ZIP Code Tabulation Area geography, in square miles; density is population ÷ land area, computed by this site. Earlier versions of the site showed rough area and density values that did not agree with each other; they were replaced with these Census figures in October 2026.
City and county descriptions are short factual notes. Official city and county population totals are not shown until they have been checked against the Census Bureau's published counts; the residents figures on those pages are the sum of the ZIPs on this site.
7. Known limitations
- ACS estimates are survey-based, with margins of error that grow as population shrinks. Small differences between ZIPs, and any figure for a ZIP under 5,000 residents, should not be over-read.
- Median home value is the owner's own estimate from the ACS questionnaire, not a sale price.
- Median gross rent includes utilities and covers all occupied rentals, including long-held and rent-stabilized leases, so it runs below current asking rents.
- ZIPs with many students show low median incomes that describe residents, not the buyer or renter pool.
- Medians describe areas, not households. A rent burden over 30% means the typical rent is high against the typical income in that ZIP, not that every renter there is cost-burdened.
- The Los Angeles ZIP median counts each ZIP once. It is not the citywide median the Census Bureau publishes for the City of Los Angeles.
8. Updates
The Census Bureau releases new ACS 5-year estimates about once a year. When the dataset is rebuilt from a new release, every rank, median and sentence on the site is regenerated from it by the same code.
9. Corrections
When a figure is corrected, the change is made in the dataset, so every page that uses it updates together. More about the site is on the About page.