San Marcos city, California
Official LSAD Designation: San Marcos city • Census GEOID: 0668196
• San Diego County
Demographics & Population Profile
Population and demographics for San Marcos city.
| Demographic Variable | Estimate / Count | Margin of Error | Period | Source |
|---|---|---|---|---|
| Total Population (2025 PEP Estimate) | 94,908 | — | 2025 | Census |
| Median Age | 36.8 yrs | ±1.1 | 2020-2024 | Census ACS 5-Year 2024 |
| Total Households | 31,350 | ±806 | 2020-2024 | Census ACS 5-Year 2024 |
Source: U.S. Census Bureau (PEP, ACS 5-Year).