Total Population in New Castle County, DE

ACS 2024 5-Year Estimates

Total Population
577,961
Rank #122 of 3,222
96th percentile

How New Castle County Compares

New Castle County
577,961
Delaware Average
577,961
Rank #1 of 3 in state
National
330M
99.8% below

National Distribution

Where New Castle County falls among all 3,222 U.S. counties for total population.

33 9,808,667

■ New Castle County: 577,961

Ranking Context

Rank County Value
#119 Jefferson County, CO 579,377
#120 Union County, NJ 579,290
#121 Delaware County, PA 579,222
#122 New Castle County, DE 577,961
#123 Baltimore city, MD 573,243
#124 Dane County, WI 572,674
#125 South Central Connecticut Planning Region, CT 570,598
View full ranking →

Total Population in New Castle County, Delaware

New Castle County, Delaware has a total population of 577,961, which ranks #122 of 3,222 out of 3,222 counties nationwide. This is 99.8% below the national value of 330M.

Within Delaware, New Castle County ranks #1 of 3 out of 3 counties. This places it in the 96th percentile nationally.

Total population count from the American Community Survey. All data comes from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates for 2024.

About this data

Source: U.S. Census Bureau, American Community Survey 5-Year Estimates (2024). All values are estimates derived from survey samples and are subject to margin of error. For more information, see our methodology.