Ada County's 2026 population is estimated at 554,017, reflecting a 1.67% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Ada County is the largest county in Idaho. The 2010 population was 393,369 and has grown 40.84% since 2010.
Data after 2023 is projected based on recent change
Overall: 38.4 years
Female: 39.4 years
Male: 37.6 years
There are 404,742 adults, (84,270 of whom are seniors) in Ada County.
Female: 257,481 (49.6%)
Male: 261,454 (50.4%)
The racial composition of Ada County includes 83.11% White, and smaller percentages for other race, Asian, Black or African American, Native American, Native Hawaiian or Pacific Islander and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 431,302 | 83.11% |
| Two or more races | 46,879 | 9.03% |
| Other race | 15,173 | 2.92% |
| Asian | 14,278 | 2.75% |
| Black or African American | 6,901 | 1.33% |
| Native American | 3,444 | 0.66% |
| Native Hawaiian or Pacific Islander | 958 | 0.18% |
Ada County 's average per capita income is $54,685. Household income levels show a median of $91,502. The poverty rate stands at 8.34%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $124,084 | $162,104 |
| Families | $111,682 | $147,069 |
| Households | $91,502 | $124,631 |
| Non Families | $57,534 | $76,107 |
Average Income
Median Household Income
Poverty Rate
