E-2. California County Population Estimates and Components of Change by Year — July 1, 2020-2024

December 2024

OFFICIAL STATE ESTIMATES

Contents

This report presents preliminary state and county population estimates for July 1, 2024, revised estimates for July 1, 2020, July 1, 2021, July 1, 2022, July 1, 2023, and components of population change.

Highlights

California’s population grew by about 49,000, or 0.12 percent, in the year ending July 1, 2024, reaching 39,172,742, according to new data released today by the California Department of Finance. The 0.12 percent increase marks the state’s return to population growth following three years of consecutive declines during the pandemic and reflects the combination of several factors:

  • Legal immigration continued to rebound from the pandemic, with a net gain of 134,400 persons in 2023-24 compared to 115,900 in 2022-23—the highest level since 2018.
  • Greater domestic in-migration and slowed domestic out-migration helped to bring net loss in domestic migration down to below 200,000 persons in 2023-24 from nearly 250,000 persons in 2022-23. Net domestic migration from California in 2023-2024 has dropped significantly, to about one-sixth of the 2021 total and is similar to levels prior to 2018.
  • Natural increase—the net result of births minus deaths—increased from 107,400 in 2022-23 to 111,500 in 2023-24 as the number of deaths return to trend from their pandemic peak.

For nearly 20 years, California has experienced negative net domestic migration, in which the number of people moving out of the state in a year exceeds the number moving in. Since 2016, net domestic outmigration has exceeded net international migration, leaving natural increase as the only source of population growth. Natural increase is constrained by continuing fertility declines and increased deaths from an aging population.

Net international migration to California reached 134,400 people in the year ending July 2024, a significant positive for overall population growth. However, negative domestic net migration still outweighed these gains, resulting in a net migration loss of over 62,600 residents.

With increasing international migration and deaths returning to long-term trends, a stable foundation for continued growth has returned. California is likely to experience slow but positive growth for the near future as net domestic migration is expected to recede to the lower rates of the 2010s.

Methodology

The state and county population are independently estimated using population change models benchmarked on official decennial census counts. The state population is estimated using the Driver License Address Change method. County population proportions are estimated using the average of three separately estimated sets of proportions. The final distribution of proportions is applied to the independently estimated state control.

State Estimate. The state population is estimated using the Driver License Address Change (DLAC) Method. This composite method separately estimates the population under age 18, 18 through 64, and 65 years and older. Administrative records such as births, deaths, driver license address changes, tax return data, Medicare and Medi-Cal enrollment, immigration reports, elementary school enrollments, and group quarters population are among the data used in this method. All data used to develop these estimates are in summary tables and do not reveal the identity of any individual.

County Estimates. Most of county populations estimates result from averaging the first three methods below. We use a Vital Statistics Method in nine counties with 65,000 populations or less.

DLAC Method. A modified version of the state Driver License Address Change (DLAC) method is used for counties. County proportions of the state total result from changes in county population values for births, deaths, school enrollment, foreign and domestic migration, medical care and medical aid enrollments, and group quarters population.

Ratio-Correlation Method. This method models change in household population as a function of changes in the distributions of driver licenses, school enrollments, and housing units. Estimates of county group quarters are added.

Tax Return Method. County proportions are derived by the U.S. Census Bureau using matched federal income tax returns to estimate inter-county migration along with vital statistics, group quarters, and other information for the population aged 65 and over.

Vital Statistics Method. County population estimates result from changes in county population values for births, deaths, and group quarters population.

Data Considerations

Sources. Data used in estimation models come from administrative records of numerous state and federal departments and agencies. Timeliness and coverage in these series vary. Corrections, adjustments or estimates may be made while preparing the estimates.

Accuracy. In general, estimates become less precise as the time from the last census increases. Data and models used to produce population estimates are subject to both measurement and non-measurement errors. This results in imperfect correlation between the data used to estimate the population and actual population change. The data and estimating models have been thoroughly tested with decennial census results that provide benchmarks for the estimates series. Data and methods are further refined and modified throughout the decade.

Acknowledgments

Phuong Nguyen produced the state and county estimates and prepared this report. Andres Gallardo produced the birth and death data. Douglas Kuczynski and John Boyne collected and prepared the group quarters data. Alex Alvarado produced the school enrollment projections. John Boyne validated input data, formulas, and methodologies used in the current state and county estimates series.

Suggested Citation

State of California, Department of Finance, E-2. California County Population Estimates and Components of Change by Year, July 1, 2020-2024. Sacramento, California, December 2024.