Grundy County's 2026 population is estimated at 12,391, reflecting a -0.06% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Grundy County is the 61st largest county in Iowa. The 2010 population was 12,464 and has grown -0.59% since 2010.
Data after 2023 is projected based on recent change
Overall: 41.9 years
Female: 42.7 years
Male: 41 years
There are 9,479 adults, (2,600 of whom are seniors) in Grundy County.
Female: 6,253 (50.5%)
Male: 6,131 (49.5%)
The racial composition of Grundy County includes 95.1% White, and smaller percentages for Two or more races, other race, Black or African American, Asian, Native American and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 11,777 | 95.1% |
| Two or more races | 228 | 1.84% |
| Other race | 191 | 1.54% |
| Black or African American | 71 | 0.57% |
| Asian | 59 | 0.48% |
| Native American | 58 | 0.47% |
Grundy County 's average per capita income is $51,929. Household income levels show a median of $87,205. The poverty rate stands at 6.52%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $113,936 | - |
| Families | $104,675 | $119,414 |
| Households | $87,205 | $101,039 |
| Non Families | $42,414 | $57,620 |
Average Income
Median Household Income
Poverty Rate