Riverside County vs San Diego County
Two neighbouring counties in California, compared on population, size, income and housing. They share 86 mi of border.
Riverside County
California
San Diego County
California
Both outlines are drawn at true relative size. Riverside County spans about 295.7 km at its widest.
Side by side
| Measure | Riverside County | Difference | San Diego County |
|---|---|---|---|
| Population | 2,544,916 | -22.5% | 3,282,248 |
| Change since 2020 | 5.0% | +5.6 pp | -0.6% |
| Land area | 7,209 sq mi | +71.2% | 4,211 sq mi |
| Population density | 353 per sq mi | -54.7% | 779 per sq mi |
| Median household income | $93,074 | -12.4% | $106,268 |
| Median home value | $557,300 | -34.8% | $854,700 |
| Median age | 37.0 | -0.8% | 37.3 |
| Households | 775,335 | -33.8% | 1,171,278 |
| Housing units | 869,414 | -30.5% | 1,250,641 |
Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026; US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. The difference column is computed here: the first county's figure against the second, expressed as a percentage of the second. The change-since-2020 row is the exception: two growth rates differ in percentage points (pp), not percent. Retrieved 30 August 2026.
What the numbers say
- San Diego County holds about 1.3 times the population of Riverside County: 3,282,248 against 2,544,916.
- Riverside County covers more ground, at 7,209 square miles against 4,211.
- San Diego County is the more crowded of the two, at 779 people per square mile against 353.
- Median household income is higher in San Diego County, by 13,194 dollars a year.
- Since 2020, Riverside County has grown by 5.0% and San Diego County has shrunk by 0.6%.
- They share 86 mi of common border, which the Census Bureau publishes in its county adjacency file and which almost no other county reference presents.
Full pages
Want a different pair? Compare any two of the 3,144 US counties.
Rebuilt from source data 30 August 2026. How these figures are produced.