U.S. county atlas · Research index
A community-focused report for California families, local reporters and aging organizations. Explore all 58 counties, with Census source periods, margins of error and reusable evidence.
What does ± mean? These survey figures are estimates. The ± value shows their sampling uncertainty: for example, 30.8% ±0.6 percentage points gives a range of 30.2%–31.4%. A wider range means a less precise estimate. How the confidence level works.
California’s statewide picture
California’s estimated living-alone count increased while its share of the older population decreased. Those measures can move in different directions when the denominator grows faster than the numerator. This is a statewide demographic description; it is not evidence of improved support networks or reduced planning needs.
Older residents living alone
2020–2024 ACS estimate; count uncertainty ±10,162.
Share of all residents age 65+
estimate uncertainty ±0.15 percentage points.
The earlier 2015–2019 estimate was 1,240,288 older residents living alone, or 22.6% of older residents. The count rose 8.6%; the share changed by -0.74 percentage points (change uncertainty ±0.20 pp). The statewide share difference exceeds that unadjusted change margin.
The older-resident denominator rose 12.3% to 6,158,371. That arithmetic helps explain how count growth and share change relate; it does not identify the social causes of either pattern. The U.S. point-estimate share is 26.6%. California’s point estimate is 4.7 percentage points lower, but this report does not test a state-versus-national difference.
Local findings worth examining
Los Angeles: scale and prevalence answer different questions
Los Angeles has the largest estimated count of older adults living alone in California. Its population scale makes the count useful for describing the number of households, but the share provides a different comparison. A large count does not establish an unusually high probability that any individual older resident lives alone.
The 2020–2024 estimate is 312,361 residents age 65+ living alone (count uncertainty ±3,712), representing 21.0% of all older residents (share margin ±0.22 percentage points).
The share change from 2015–2019 is -0.92 pp, with an change uncertainty ±0.30 pp. The change is supported after correction across the national family of 3,133 comparable county tests. Explore this county and its source table.
San Francisco: a higher-share urban example
San Francisco provides a different urban story from Los Angeles. The county share is above the state point estimate, but this analysis does not test that difference or explain its causes. Housing patterns, household choices and demographics would require additional evidence and reporting.
The 2020–2024 estimate is 42,888 residents age 65+ living alone (count uncertainty ±1,220), representing 29.3% of all older residents (share margin ±0.67 percentage points).
The share change from 2015–2019 is -0.46 pp, with an change uncertainty ±1.00 pp. The change is not established after correction across the national family of 3,133 comparable county tests. Explore this county and its source table.
Colusa: why small-county estimates need their margins
Colusa has a high point-estimate share, accompanied by a much wider margin than the state result. It is an example of why a dramatic percentage should not become a definitive county ranking. A large apparent change also requires its own uncertainty assessment, not just subtraction of two percentages.
The 2020–2024 estimate is 1,266 residents age 65+ living alone (count uncertainty ±236), representing 37.1% of all older residents (share margin ±5.96 percentage points).
The share change from 2015–2019 is +8.38 pp, with an change uncertainty ±7.31 pp. The change is not established after correction across the national family of 3,133 comparable county tests. Explore this county and its source table.
All California counties
This table includes all 58 counties, rather than only a ranked shortlist. Share-change labels use the nationwide multiple-comparison procedure, not a separate set of tests selected for California. Counts and shares are point estimates. Sorting by share does not establish statistically distinct ranks.
Open the interactive California county map · Download all California counties (CSV)
| County / equivalent | State | Age 65+ living alone | Share | estimate uncertainty | Share change |
|---|---|---|---|---|---|
| Los Angeles County | California | 312,361±3,712 | 21.0% | ±0.22 pp | -0.92 ppSupported change |
| San Diego County | California | 109,758±2,378 | 21.6% | ±0.43 pp | -0.74 ppNot established |
| Orange County | California | 100,844±2,171 | 19.6% | ±0.38 pp | -1.31 ppSupported change |
| Riverside County | California | 78,142±1,891 | 20.4% | ±0.45 pp | -0.86 ppNot established |
| Sacramento County | California | 62,227±1,626 | 25.6% | ±0.58 pp | +0.49 ppNot established |
| Alameda County | California | 55,722±1,693 | 21.9% | ±0.61 pp | -1.89 ppSupported change |
| San Bernardino County | California | 52,725±1,879 | 19.0% | ±0.64 pp | -0.48 ppNot established |
| Santa Clara County | California | 52,413±1,460 | 18.6% | ±0.47 pp | -0.64 ppNot established |
| Contra Costa County | California | 43,940±1,457 | 22.1% | ±0.67 pp | -0.38 ppNot established |
| San Francisco County | California | 42,888±1,220 | 29.3% | ±0.67 pp | -0.46 ppNot established |
| Ventura County | California | 31,156±1,186 | 21.4% | ±0.73 pp | +0.47 ppNot established |
| Fresno County | California | 30,735±1,270 | 23.4% | ±0.87 pp | -1.63 ppNot established |
| Sonoma County | California | 28,627±1,163 | 27.4% | ±0.99 pp | -1.08 ppNot established |
| San Mateo County | California | 26,222±1,124 | 19.8% | ±0.79 pp | -1.78 ppSupported change |
| Kern County | California | 24,219±1,158 | 22.3% | ±0.96 pp | -1.88 ppNot established |
| San Joaquin County | California | 22,445±1,074 | 20.8% | ±0.91 pp | -0.93 ppNot established |
| Placer County | California | 19,863±962 | 23.1% | ±1.03 pp | -0.83 ppNot established |
| Santa Barbara County | California | 18,311±813 | 24.8% | ±0.97 pp | -0.57 ppNot established |
| Marin County | California | 17,820±797 | 29.0% | ±1.09 pp | -1.03 ppNot established |
| Solano County | California | 17,096±910 | 21.7% | ±1.05 pp | +1.14 ppNot established |
| Stanislaus County | California | 17,076±1,015 | 22.4% | ±1.23 pp | +0.41 ppNot established |
| San Luis Obispo County | California | 15,264±886 | 24.5% | ±1.27 pp | +0.85 ppNot established |
| Monterey County | California | 13,763±751 | 21.2% | ±1.05 pp | -1.49 ppNot established |
| Santa Cruz County | California | 12,738±812 | 25.3% | ±1.47 pp | -0.71 ppNot established |
| Tulare County | California | 11,110±815 | 19.5% | ±1.32 pp | -2.69 ppSupported change |
| Shasta County | California | 10,595±615 | 27.2% | ±1.35 pp | +1.00 ppNot established |
| Butte County | California | 10,270±628 | 26.9% | ±1.43 pp | +0.43 ppNot established |
| El Dorado County | California | 9,853±727 | 21.8% | ±1.48 pp | +1.07 ppNot established |
| Merced County | California | 7,888±594 | 23.2% | ±1.55 pp | +1.15 ppNot established |
| Humboldt County | California | 7,570±483 | 28.4% | ±1.50 pp | -2.08 ppNot established |
| Yolo County | California | 7,542±548 | 25.4% | ±1.66 pp | +0.30 ppNot established |
| Nevada County | California | 7,394±625 | 24.6% | ±1.84 pp | +1.66 ppNot established |
| Mendocino County | California | 7,014±536 | 31.7% | ±1.99 pp | +2.14 ppNot established |
| Napa County | California | 6,867±1,530 | 24.1% | ±5.11 pp | -2.24 ppNot established |
| Imperial County | California | 5,157±499 | 20.9% | ±1.78 pp | +2.73 ppNot established |
| Madera County | California | 4,635±485 | 20.0% | ±1.93 pp | +2.12 ppNot established |
| Lake County | California | 4,569±472 | 28.0% | ±2.57 pp | -3.57 ppNot established |
| Tuolumne County | California | 4,320±431 | 28.2% | ±2.41 pp | +1.38 ppNot established |
| Kings County | California | 3,670±412 | 22.1% | ±2.22 pp | +2.11 ppNot established |
| Sutter County | California | 3,403±367 | 21.0% | ±2.01 pp | -1.84 ppNot established |
| Siskiyou County | California | 3,205±306 | 26.5% | ±2.25 pp | -4.77 ppSupported change |
| Tehama County | California | 3,166±366 | 24.2% | ±2.43 pp | -0.82 ppNot established |
| Yuba County | California | 2,907±433 | 26.3% | ±3.60 pp | -0.13 ppNot established |
| Calaveras County | California | 2,811±448 | 20.8% | ±3.06 pp | -0.80 ppNot established |
| Amador County | California | 2,495±331 | 21.8% | ±2.57 pp | -0.46 ppNot established |
| San Benito County | California | 1,717±251 | 18.6% | ±2.52 pp | +2.95 ppNot established |
| Lassen County | California | 1,636±205 | 32.6% | ±3.33 pp | +5.40 ppNot established |
| Del Norte County | California | 1,540±250 | 27.7% | ±3.87 pp | +0.93 ppNot established |
| Plumas County | California | 1,510±279 | 24.7% | ±4.06 pp | -0.25 ppNot established |
| Inyo County | California | 1,458±218 | 31.2% | ±3.84 pp | +0.07 ppNot established |
| Colusa County | California | 1,266±236 | 37.1% | ±5.96 pp | +8.38 ppNot established |
| Mariposa County | California | 1,177±235 | 23.2% | ±4.08 pp | -3.08 ppNot established |
| Trinity County | California | 1,143±274 | 23.8% | ±4.95 pp | -5.22 ppNot established |
| Glenn County | California | 1,133±198 | 23.2% | ±3.63 pp | +0.64 ppNot established |
| Modoc County | California | 667±193 | 24.5% | ±6.09 pp | -3.15 ppNot established |
| Mono County | California | 421±174 | 18.3% | ±7.08 pp | -6.66 ppNot established |
| Sierra County | California | 303±115 | 31.5% | ±10.91 pp | +7.59 ppNot established |
| Alpine County | California | 43±24 | 12.6% | ±6.36 pp | -7.33 ppNot established |
A chart for local reporting
The chart shows ten highest point-estimate shares among California counties with at least 10,000 residents age 65+. That population cutoff is an editorial choice for readability, not an official Census threshold. All counties remain in the table and download above. Error bars indicate estimate uncertainty; the chart does not establish distinct ranks.

Download California chart (PNG) · Download charts, analysis and methodology (ZIP)
Questions for California reporters and organizations
For California reporting, distinguish populous counties such as Los Angeles from smaller counties whose shares can carry wide margins. San Francisco and Colusa offer different ways to discuss a high point estimate. Avoid describing the first county in a sorted table as the definitively highest true share. Interview local residents and organizations separately from the statistical description.
Ask which communities are represented by an estimate, whether services use the same geography, and which period the source describes. A county total is not a service-demand estimate. Living alone does not establish loneliness, a lack of family contact, incapacity or an absent estate plan. A survey percentage should not be used to diagnose a person.
Practical next steps for California families
The local data can start a conversation, but family preparation depends on actual circumstances. Confirm emergency contacts, where important records are kept, and who has agreed to help. Our California estate-planning guide organizes the state-specific questions.
- California will requirements and costs — understand what a will does and the signing questions.
- California living-trust costs — compare scope and expenses if you are evaluating a trust.
- Essential estate-planning documents — organize the financial and healthcare document conversation.
The atlas does not recommend buying a particular package because someone lives alone. Readers choosing a planning approach can compare a will and a trust; readers seeking local aging services can use the official Eldercare Locator.
Sources, definitions and reuse
Source: Census ACS five-year tables B11010 and B01001, 2020–2024 and 2015–2019. The numerator sums male/female householders age 65+ living alone, one person per household. It excludes group quarters. The denominator includes all older residents, including group quarters, so the measure answers what share of all older residents live alone.
Census publishes margins of error at a 90% confidence level; sums, proportions and differences use approximate Census formulas. Covariance is approximated, not calculated from variance replicates. National county-change labels use Benjamini–Hochberg at 10% false discovery rate across 3,133 comparable tests. See the national methodology and geography limitations or download complete calculation notes. Historical comparisons match identifiers; minor boundary changes are not harmonized.
Initial California community edition, September 17, 2026. Survey estimates are not 2026 headcounts. Editorial standards.