New Castle County, DE Demographics
New Castle County, DE is the most populous of 3 counties in Delaware, with 570,573 residents across 426 square miles. That is about 1,338 people per square mile.
At the 2020 census
| Population | 570,573 |
|---|---|
| Land area | 426 sq mi |
| Density | 1,338 / sq mi |
Data: 2020 Census · American Community Survey 2024
How New Castle County compares to the US
We're computing this county's comparison table — check back shortly. Population, land area, and density above are already exact.
Central Location: New Castle County, DE
Measured from the county's main population center using 2020 census blocks.
We're computing the drive-time and radius areas around New Castle County, DE — check back shortly. Meanwhile you can drop a pin anywhere in the radius tool.
Census tracts in New Castle County, DE
Showing the 100 most populous of 144 — the rest are shown on the map.
Related places
Other counties nearby
Nearest counties
Metro areas containing New Castle County
About this page
This page shows demographics for a US county from the 2020 census and the American Community Survey: population, land area, density, urban share, and how the county compares to national averages for income, housing, age, and more.
Counties subdivide into census tracts, listed below with their populations. The drive-time and radius tables measure the population around the county's main population center.