Ada County, Idaho Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 1st-largest in Idaho
The population of Ada County, Idaho is 508,052 as of the 2023 American Community Survey, making it the 1st-largest county in Idaho. The median household income is $88,907, the median home value is $476,000, and the median age is 38.3.
The population of Ada County has grown 36.2% since 2010 (393,369 → 535,799), a +2.23% annualized rate.
508,052
Population
+2.23%
Annual growth
483
People / sq mi
$88,907
Median Income
$476,000
Median Home Value
Ada County covers 1,052 sq mi of land at 482.8 people per square mile.
About Ada County, ID
Housing cost is the defining feature of Ada County: the median home is valued at $476,000. Ada County is a county in Idaho with a population of 508,052. It is the #1-largest of all counties in Idaho nationally.
Earnings sit at the high end: a median household income of $88,907, above the US median of $78,538. The poverty rate, 5.5%, is on the lower side for US counties and below the national 12.4%. Home prices are steep, with the typical property valued at $476,000, with typical rent around $1,465.
The population is unusually well-credentialed for US counties — 43.9% of adults have a four-year degree, above the national 35.0%. Remote work is widespread — 16.8% of workers stay home, above the national 14.0%, and the average commute runs about 21 minutes each way.
High housing values reframe the income picture in Ada County — even solid earnings stretch less against home prices and rents at this level.
Ada County Population History (2010-2024)
The county of Ada County had a population of 393,369 in 2010 and 535,799 in 2024, a 36.2% growth over 14 years. The peak was 535,799 in 2024. Average annual growth rate: 2.23%.
535,799
Population (2024)
393,369
Population (2010)
535,799
Peak (2024)
2.23%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 393,369 |
| 2011 | 401,352 |
| 2012 | 409,032 |
| 2013 | 416,180 |
| 2014 | 425,774 |
| 2015 | 433,254 |
| 2016 | 444,929 |
| 2017 | 456,994 |
| 2018 | 469,161 |
| 2019 | 481,880 |
| 2020 | 498,301 |
| 2021 | 513,098 |
| 2022 | 520,788 |
| 2023 | 526,690 |
| 2024 | 535,799 |
Race & Ethnicity
| White | 84.8% |
| Black or African American | 1.3% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 2.2% |
| Two or More Races | 0.0% |
Age & Sex
38.3
Median Age
49.6%
Female
50.4%
Male
15.8%
Age 65+
Age Distribution
Children (under 15): 18.2% · Seniors (65+): 15.8%
Income & Poverty
| Median household income | $88,907+$14,271 vs state |
| Mean household income | $121,034 |
| Per-capita income | $47,768 |
| Poverty rate | 5.5%-1.5% vs state |
| Unemployment rate | 2.1% |
| Employment-to-population | 64.1% |
Top Industries by Employment
The largest employment sector in Ada County is professional & business services, accounting for 22.7% of workers.
How residents commute
0.4%
Drive alone
2.3%
Carpool
70.6%
Public transit
16.8%
Work from home
21.2 min
Avg commute
Housing
$476,000+$100,000 vs state
Median home value
$1,465
Median rent
71.4%
Homeownership rate
205,068
Total housing units
95.9%
Occupied
4.1%
Vacant
28.6%
Renter-occupied
Social & access
93.3%
With health insurance
97.8%
With broadband internet
53.5%
Foreign-born
8.0%
Veterans (18+)
11.2%
With a disability
91.0%
Speak language other than English at home
Education
95.1%
High School+
43.9%
Bachelor's+
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County rankings
Common questions about Ada County, ID
Frequently Asked Questions
Ada County, Idaho has a population of 508,052 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 1st-largest county in Idaho. Population density is 483 people per square mile.
The population of Ada County has grown 36.2% since 2010 (393,369 → 535,799), a +2.23% annualized rate.
The median household income in Ada County, Idaho is $88,907, with mean (average) household income of $121,034 and per-capita income of $47,768. 5.5% of residents live below the federal poverty level.
In Ada County, the largest racial and ethnic groups are White (84.8%), Hispanic or Latino (2.2%), Black or African American (1.3%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Ada County, Idaho is 38.3 years. Residents are 49.6% female and 50.4% male.
The median home value in Ada County is $476,000 and median monthly rent is $1,465. 71.4% of occupied housing units are owner-occupied. The county has 205,068 total housing units, 4.1% of which are vacant.
The largest employment sector in Ada County, Idaho is professional, scientific, and management services, employing 22.7% of workers. The unemployment rate is 2.1%.
Boise City is among the largest cities associated with Ada County, Idaho, with a population of 235,701.
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Statewide data for Idaho
Population, race, income, age, and trends across Idaho
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.