Home / San Mateo County, CA
Pick an industry to see how saturated it is across San Mateo County's ZIP codes, compared with the U.S. average. All figures use Census ZBP 2023 + ACS 2024.
Population. Census estimates 742,893 residents on July 1, 2024, 2.6% below 2020 (−19,834).
Latest year (2023→2024): births minus deaths +2,180, international migration +12,450, domestic migration −6,006. These are model-based estimates built from births, deaths, and migration, revised annually — not a census count, and they can differ from the ACS 5-year figure used elsewhere on the site. Components may not sum exactly because of rounding.
Jobs. LODES counts 423,564 jobs located in the county in 2022 (+5.7% since 2019) and 369,131 employed residents (−5.5% since 2019). A job and a worker are not the same thing: the first is measured at the workplace, the second at the home address, and one person can hold two jobs. Self-employed, military, and informal work are excluded.
Where movers come from and go. IRS matched individual tax returns between 2021 and 2022. 33,547 people (exemptions) moved into San Mateo County, reporting $4.75B in adjusted gross income; 45,162 moved out, reporting $7.37B. Net: −11,615 people.
Largest sources: San Francisco, CA (7,784) · Santa Clara, CA (6,543) · Alameda, CA (3,228). Largest destinations: Santa Clara, CA (6,869) · San Francisco, CA (5,148) · Alameda, CA (4,840).
People are exemptions on matched returns — not a population estimate. Non-filers, dependents claimed elsewhere, and people whose address did not change are treated differently than in Census estimates. Tax data lag about two years.
Each source is reported at its own geography and year. None of them measures demand for a specific business type; they describe whether the local customer base and job base are expanding or shrinking. Definitions and limits →
ACS 5-year estimates for 2015–2019 and 2020–2024. Only ZIPs with at least 2,000 residents in both windows and a change larger than the survey margin of error (90%) are listed — small ZIPs move a lot on paper without a real signal.
Only ZIPs where the 2015–19→2020–24 population change is larger than the ACS margin of error and both windows have at least 2,000 residents. Sorted by population change. Jobs are LODES workplace jobs in the ZIP (2019→latest available year; 2019→2021 for Michigan, none for Alaska); a ZIP can contain more jobs than residents.
| ZIP | Neighborhood | Residents 2015–19 | Residents 2020–24 | Pop change | Jobs | Jobs change |
|---|---|---|---|---|---|---|
| 94002 | Belmont | 27,155 | 27,534 | +1.4% | 6,657 | −9.1% |
| 94066 | San Bruno | 43,101 | 42,728 | −0.9% | 13,877 | −11.8% |
| 94070 | San Carlos | 31,074 | 30,447 | −2.0% | 19,077 | +1.8% |
| 94404 | San Mateo | 36,985 | 35,881 | −3.0% | 30,189 | +5.7% |
| 94080 | South San Francisco | 67,600 | 64,761 | −4.2% | 56,866 | −0.8% |
| 94044 | Pacifica | 38,984 | 37,274 | −4.4% | 5,347 | +3.3% |
| 94027 | Atherton | 7,415 | 7,002 | −5.6% | 2,445 | −13.2% |
| 94025 | Menlo Park | 43,392 | 40,721 | −6.2% | 69,791 | +102.7% |
| 94019 | Half Moon Bay | 20,512 | 14,419 | −29.7% | 6,246 | −7.8% |
Scroll the table sideways to see all columns.
Each percentage is the county's density of that business type per 10,000 people present (residents + 0.5×workers), divided by the U.S. average. 100% = exactly average.
Density is a supply-side signal. It does not measure foot traffic, income, tourism, or whether locals actually want more of a given business.
BizGapMap — free, no-login small-business saturation reports for major U.S. counties. Built entirely from public U.S. Census, BLS, and IRS data (ZBP 2023, ACS 2024 5-year, PEP 2024, LODES, QCEW, IRS SOI). No forecasts, no revenue guesses — withheld cells are marked, and the few derived counts are labelled as estimates.