Mercer County's 2026 population is estimated at 401,249, reflecting a 0.49% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Mercer County is the 12th largest county in New Jersey. The 2010 population was 367,717 and has grown 9.12% since 2010.
Overall: 39.5 years
Female: 40.8 years
Male: 38 years
There are 301,036 adults, (61,557 of whom are seniors) in Mercer County.
Female: 195,136 (50.6%)
Male: 190,728 (49.4%)
The racial composition of Mercer County includes 46.22% White, 18.45% Black or African American, 12.44% Asian, 10.76% other race, and smaller percentages for Native American, Native Hawaiian or Pacific Islander and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 178,342 | 46.22% |
| Black or African American | 71,211 | 18.45% |
| Asian | 48,018 | 12.44% |
| Other race | 41,518 | 10.76% |
| Two or more races | 41,493 | 10.75% |
| Native American | 5,214 | 1.35% |
| Native Hawaiian or Pacific Islander | 68 | 0.02% |
Mercer County 's average per capita income is $60,967. Household income levels show a median of $100,645. The poverty rate stands at 10.27%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $157,064 | $207,561 |
| Families | $127,747 | $172,652 |
| Households | $100,645 | $142,368 |
| Non Families | $55,531 | $78,877 |
Average Income
Median Household Income
Poverty Rate