County facts · Population · October 24, 2026
California Population by County, 2025 Census Estimates
California population by county: July 2025 Census estimates for all 58 counties, change since 2020, density, and a link to each official parcel map.
Looking for California population by county? The Census Bureau estimates that California had 39,355,309 residents on July 1, 2025, spread across 58 counties. Los Angeles County is the most populous, with 9,694,934 people (25% of the state), and Alpine County is the least populous, with 1,043.
The table below lists every county with its 2025 estimate, its April 2020 starting point, the change, people per square mile, and a link to its official parcel viewer.
California population at a glance
- Counties: 58
- Statewide, July 1, 2025: 39,355,309 (April 1, 2020 estimates base: 39,555,703; change −200,394, −0.5%)
- Most populous: Los Angeles County (9,694,934); least populous: Alpine County (1,043)
- Median county: about 186,986 residents (half of the counties are smaller)
- The 5 largest counties hold 53% of all California residents
- Counties with 1,000,000+ residents: 10 · 100,000+: 36 · under 10,000: 3
- Statewide density: about 253 people per square mile of land
California population by county, July 2025 (all 58)
| # | County | Jul 2025 | Apr 2020 | % change | People per sq mi | Parcel viewer |
|---|---|---|---|---|---|---|
| 1 | Los Angeles County | 9,694,934 | 10,017,414 | −3.2% | 2,388 | county web map |
| 2 | San Diego County | 3,282,248 | 3,298,648 | −0.5% | 780 | ArcGIS Map Viewer |
| 3 | Orange County | 3,149,507 | 3,187,279 | −1.2% | 3,972 | county web map |
| 4 | Riverside County | 2,544,916 | 2,419,962 | +5.2% | 353 | county web map |
| 5 | San Bernardino County | 2,224,091 | 2,181,653 | +1.9% | 111 | county web map |
| 6 | Santa Clara County | 1,914,391 | 1,936,274 | −1.1% | 1,483 | county web map |
| 7 | Alameda County | 1,636,630 | 1,682,246 | −2.7% | 2,219 | ArcGIS Web AppBuilder |
| 8 | Sacramento County | 1,618,460 | 1,585,027 | +2.1% | 1,677 | county web map |
| 9 | Contra Costa County | 1,170,070 | 1,166,035 | +0.3% | 1,632 | county web map |
| 10 | Fresno County | 1,035,456 | 1,008,661 | +2.7% | 174 | ArcGIS Web AppBuilder |
| 11 | Kern County | 927,068 | 909,227 | +2.0% | 114 | county web map |
| 12 | Ventura County | 830,851 | 844,358 | −1.6% | 451 | county web map |
| 13 | San Francisco County | 826,079 | 878,550 | −6.0% | 17,608 | county web map |
| 14 | San Joaquin County | 823,815 | 779,234 | +5.7% | 592 | county web map |
| 15 | San Mateo County | 743,568 | 764,508 | −2.7% | 1,657 | county web map |
| 16 | Stanislaus County | 557,719 | 553,284 | +0.8% | 373 | listed link under review |
| 17 | Sonoma County | 486,444 | 488,860 | −0.5% | 309 | county web map |
| 18 | Tulare County | 485,146 | 473,118 | +2.5% | 101 | ArcGIS Web AppBuilder |
| 19 | Solano County | 455,376 | 453,556 | +0.4% | 554 | ArcGIS Web AppBuilder |
| 20 | Placer County | 442,081 | 404,767 | +9.2% | 314 | ArcGIS Experience Builder |
| 21 | Santa Barbara County | 442,065 | 448,214 | −1.4% | 162 | ORMAP |
| 22 | Monterey County | 433,729 | 441,022 | −1.7% | 132 | county web map |
| 23 | Merced County | 297,260 | 282,457 | +5.2% | 153 | listed link under review |
| 24 | San Luis Obispo County | 282,367 | 282,440 | −0.0% | 86 | county web map |
| 25 | Santa Cruz County | 258,852 | 272,163 | −4.9% | 582 | county web map |
| 26 | Marin County | 253,694 | 262,312 | −3.3% | 487 | county web map |
| 27 | Yolo County | 224,410 | 217,871 | +3.0% | 221 | ArcGIS Experience Builder |
| 28 | Butte County | 209,211 | 211,629 | −1.1% | 128 | ArcGIS Web AppBuilder |
| 29 | El Dorado County | 192,323 | 191,189 | +0.6% | 113 | ArcGIS Experience Builder |
| 30 | Shasta County | 181,648 | 182,452 | −0.4% | 48 | ArcGIS Map Viewer |
| 31 | Imperial County | 181,411 | 179,705 | +0.9% | 43 | ArcGIS Web AppBuilder |
| 32 | Madera County | 167,927 | 156,258 | +7.5% | 79 | listed link under review |
| 33 | Kings County | 154,327 | 152,480 | +1.2% | 111 | ArcGIS Web AppBuilder |
| 34 | Napa County | 132,949 | 138,023 | −3.7% | 178 | listed link under review |
| 35 | Humboldt County | 131,647 | 136,462 | −3.5% | 37 | ArcGIS Experience Builder |
| 36 | Nevada County | 101,911 | 102,234 | −0.3% | 106 | ArcGIS Experience Builder |
| 37 | Sutter County | 98,787 | 99,632 | −0.8% | 164 | county web map |
| 38 | Yuba County | 88,691 | 81,573 | +8.7% | 140 | ArcGIS Map Viewer |
| 39 | Mendocino County | 88,122 | 91,585 | −3.8% | 25 | ArcGIS Map Viewer |
| 40 | San Benito County | 70,082 | 64,205 | +9.2% | 50 | ArcGIS Experience Builder |
| 41 | Lake County | 67,772 | 68,162 | −0.6% | 54 | ArcGIS Web AppBuilder |
| 42 | Tehama County | 64,665 | 65,912 | −1.9% | 22 | county web map |
| 43 | Tuolumne County | 53,160 | 55,612 | −4.4% | 24 | listed link under review |
| 44 | Calaveras County | 46,605 | 45,285 | +2.9% | 46 | ArcGIS Web AppBuilder |
| 45 | Siskiyou County | 42,013 | 44,076 | −4.7% | 6.7 | ArcGIS Experience Builder |
| 46 | Amador County | 41,876 | 40,487 | +3.4% | 70 | ArcGIS Experience Builder |
| 47 | Glenn County | 28,141 | 28,910 | −2.7% | 21 | ArcGIS Instant Apps |
| 48 | Lassen County | 28,117 | 32,729 | −14.1% | 6.2 | ArcGIS Experience Builder |
| 49 | Del Norte County | 26,410 | 27,749 | −4.8% | 26 | ArcGIS Experience Builder |
| 50 | Colusa County | 21,836 | 21,835 | +0.0% | 19 | ArcGIS Web AppBuilder |
| 51 | Plumas County | 18,583 | 19,794 | −6.1% | 7.3 | county web map |
| 52 | Inyo County | 18,158 | 19,020 | −4.5% | 1.8 | ArcGIS Web AppBuilder |
| 53 | Mariposa County | 16,918 | 17,133 | −1.3% | 12 | ArcGIS Experience Builder |
| 54 | Trinity County | 15,720 | 16,116 | −2.5% | 4.9 | ArcGIS Experience Builder |
| 55 | Mono County | 12,505 | 13,199 | −5.3% | 4.1 | county web map |
| 56 | Modoc County | 8,426 | 8,707 | −3.2% | 2.1 | county web map |
| 57 | Sierra County | 3,098 | 3,232 | −4.1% | 3.3 | county web map |
| 58 | Alpine County | 1,043 | 1,178 | −11.5% | 1.4 | ArcGIS |
Percent change runs from the April 1, 2020 estimates base to July 1, 2025. People per square mile is the July 2025 estimate divided by the county's land area in the Census Bureau's 2020 Gazetteer file, so lakes and bays are left out.
How California's population is spread out
Grouping the counties by size shows how concentrated the state is:
| Residents (July 2025) | Counties | Total residents | Share of state |
|---|---|---|---|
| 1,000,000 or more | 10 | 28,270,703 | 72% |
| 250,000 to 999,999 | 16 | 8,546,114 | 22% |
| 100,000 to 249,999 | 10 | 1,677,764 | 4% |
| 25,000 to 99,999 | 13 | 744,441 | 2% |
| 10,000 to 24,999 | 6 | 103,720 | 0% |
| Under 10,000 | 3 | 12,567 | 0% |
26 counties with at least 250,000 residents hold 94% of the state's population.
Most and least densely populated
The most crowded counties by people per square mile of land:
- San Francisco County: 17,608 per sq mi (826,079 people on 47 sq mi)
- Orange County: 3,972 per sq mi (3,149,507 people on 793 sq mi)
- Los Angeles County: 2,388 per sq mi (9,694,934 people on 4,059 sq mi)
- Alameda County: 2,219 per sq mi (1,636,630 people on 737 sq mi)
- Sacramento County: 1,677 per sq mi (1,618,460 people on 965 sq mi)
The most thinly settled:
- Alpine County: 1.4 per sq mi (1,043 people on 738 sq mi)
- Inyo County: 1.8 per sq mi (18,158 people on 10,197 sq mi)
- Modoc County: 2.1 per sq mi (8,426 people on 3,948 sq mi)
- Sierra County: 3.3 per sq mi (3,098 people on 953 sq mi)
- Mono County: 4.1 per sq mi (12,505 people on 3,049 sq mi)
About these numbers
- They are estimates. Between censuses the Census Bureau's Population Estimates Program updates county totals each year from births, deaths and migration records. The next full count is the 2030 census.
- The base is April 1, 2020. The estimates start from an April 1, 2020 "estimates base" built from the 2020 census, which is why it is slightly different from the published census count.
- Each new release revises the past. A newer vintage can change earlier years as well, so compare numbers from the same release, as this page does.
- Statewide total. The counties add up exactly to the statewide figure of 39,355,309 in the same file.
Using population numbers in a land search
- Big counties, busy offices. In the most populous counties, parcel maps and deed records are usually online and searchable, but recording and permit offices are busier. Allow for that if you are on a deadline.
- Small counties, fewer sales. In counties with only a few thousand people, land changes hands less often, so there are fewer recent sales to compare a price with. The county assessor's sales records are the best source.
- Density hints at lot size. A low people-per-square-mile figure usually means farms, ranches and timber tracts; a high one means subdivided lots. The parcel viewer shows the actual parcel lines.
- Check the official map. Use the parcel viewer link in the table for boundaries, parcel numbers and owner names, then confirm anything important with the county's recorder or assessor.
Related guides
- Fastest growing counties in California
- Largest counties in California
- California county GIS websites by viewer
- California plat maps
- California parcel map guide
- California landowner maps for hunting
- Most populous counties in the US
- Where people are moving in the US
More: All California counties on Platbookmapper
Sources
- U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2025 (April 1, 2020 estimates base and July 1, 2020–2025 estimates, with components of change). Statewide totals are the sum of the counties and match the file's state row.
- U.S. Census Bureau Gazetteer files, 2020 county land and water area (for people per square mile).
- Platbookmapper county GIS directory (live data file behind our county pages, pulled October 24, 2026) for each official parcel viewer.