New Castle County is home to 577,961 people in Delaware. That puts it in the top 2% of US counties for household income. There are 1,356 people per square mile. 77,696 more people live here than in 2000. About 40% of adults have finished a four-year degree. Median household income runs $91,166, well clear of the $82,259 US median.
At a glance
Wealthier
median household income $91,166, above the US median
US median: $82,259
Mid-age
median age 39.3
US median: 38.9
More educated
40% hold a bachelor's degree
US average: 36%
Less affordable
home values up 45%, inflation adjusted
US median home: $376,019
Unique to this place
What stands out about New Castle County
What changed most since 1990
White share79.5% → 52.3%(−27.2 pts)US over the same years: −17.8 pts
Black share16.2% → 24.9%(+8.7 pts)US over the same years: +0.2 pts
Median home value (2024 dollars)$264,248 → $352,200(+33%)US over the same years: +67%
Shares are "alone or in combination": a person with both Medicare and Medicaid counts in each, so categories overlap and do not sum to 100%.
Section 09 · Service history
Veterans
Veterans by period of service, 2024
Gulf War (2001 or later)22.4%(5,898)
US avg: 26.4%
Gulf War (1990s)19.4%(5,106)
US avg: 24.3%
Vietnam era34%(8,941)
US avg: 33.1%
Korean War4%(1,042)
US avg: 4.5%
World War II1.3%(352)
US avg: 1%
Share of the 26,290 veterans here. A veteran who served across eras counts in each, so shares can total more than 100%. Peacetime-only service is included in the total but not shown as an era.
BAR + DOT: THIS PLACE · TICK: US AVERAGE
Over time
New Castle County, decade by decade
New Castle County population, inflation-adjusted income and home value, education, and diversity by year
Year
Population
Median household income
Median home value
Bachelor's degree+
Diversity score
1990
441,946
$92,683
$264,248
25.2%
42.6
2000
500,265
$95,489
$242,098
29.5%
57.1
2010
538,479
$89,873
$363,671
32.4%
69.6
2020
570,719
$91,236
$323,008
36.7%
79.8
2024
577,961
$91,166
$352,200
39.7%
80.5
Census years come from the decennial census and the latest year from the American Community Survey, so part of any change between those two rows can reflect the different surveys. Dollar figures are adjusted for inflation to 2024 dollars; a figure ending in "+" was at the Census Bureau's reporting cap that year. The diversity score runs from 0 to 100; see how it's calculated.
How many people live in New Castle County, Delaware?
New Castle County, Delaware has about 577,961 residents according to the 2024 American Community Survey.
What is the median household income in New Castle County, Delaware?
The typical household in New Castle County, Delaware earns about $91,166 a year. Half of households make more than that, and half make less.
Is New Castle County, Delaware expensive?
In New Castle County, Delaware, the median home is worth about $352,200, and the typical rent is about $1,448 a month.
How educated are people in New Castle County, Delaware?
About 39.7% of adults age 25 and over in New Castle County, Delaware hold a bachelor's degree or higher.
What is the poverty rate in New Castle County, Delaware?
About 10.1% of people in New Castle County, Delaware live below the federal poverty line.
Has New Castle County, Delaware grown since 1990?
Yes, New Castle County, Delaware has grown since 1990. The population has added about 136,015 residents, a change of about 31 percent over that period.