Sumner County's 2026 population is estimated at 22,222, reflecting a -0.26% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Sumner County is the 25th largest county in Kansas. The 2010 population was 24,119 and has grown -7.87% since 2010.
Data after 2023 is projected based on recent change
Overall: 41.3 years
Female: 41.7 years
Male: 40.2 years
There are 16,970 adults, (4,367 of whom are seniors) in Sumner County.
Female: 11,019 (49.3%)
Male: 11,334 (50.7%)
The racial composition of Sumner County includes 89.5% White, and smaller percentages for other race, Native American, Black or African American, Asian and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 20,007 | 89.5% |
| Two or more races | 1,400 | 6.26% |
| Other race | 337 | 1.51% |
| Native American | 278 | 1.24% |
| Black or African American | 246 | 1.1% |
| Asian | 85 | 0.38% |
Sumner County 's average per capita income is $48,246. Household income levels show a median of $63,951. The poverty rate stands at 10.64%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $102,088 | - |
| Families | $86,419 | $103,372 |
| Households | $63,951 | $83,070 |
| Non Families | $37,864 | $45,129 |
Average Income
Median Household Income
Poverty Rate