New Castle County's estimated 2025 population is 585,268 with a growth rate of 0.57% in the past year according to the most recent United States census data. New Castle County is the 1st largest county in Delaware. The 2010 population was 538,792 and has seen a growth of 8.63% since that time.
Data after 2023 is projected based on recent change
The racial composition of New Castle County includes 56.48% White, 25.28% Black or African American, 5.93% Asian, 4.68% other race, and smaller percentages for Native American, Native Hawaiian or Pacific Islander and multiracial populations.
White
Black or African American
Two or more races
Asian
Other race
Native American
Native Hawaiian or Pacific Islander
Race | Population | Percentage (of total) |
|---|---|---|
| White | 323,642 | 56.48% |
| Black or African American | 144,850 | 25.28% |
| Two or more races | 42,367 | 7.39% |
| Asian | 33,953 | 5.93% |
| Other race | 26,823 | 4.68% |
| Native American | 1,177 | 0.21% |
| Native Hawaiian or Pacific Islander | 218 | 0.04% |
Married
Widowed
Divorced
Separated
Never Married
New Castle County's average per capita income is $57,648. Household income levels show a median of $89,901. The poverty rate stands at 10.2%.
Name | Median | Mean |
|---|---|---|
| Married Families | $134,580 | $162,092 |
| Families | $112,402 | $140,270 |
| Households | $89,901 | $118,003 |
| Non Families | $54,382 | $71,246 |
Average Income
Median Household Income
Poverty Rate