New Castle Population

1850–2026

5,766

2026 projection

3.9% since 2020 (increase)

01K2K3K4K5K6K186018801900192019401960198020002020

Source: U.S. Census Bureau decennial counts and annual estimates, including 2010–2020 intercensal estimates. 2026 is a projection. Values between recorded years are interpolated.

Use the left and right arrow keys to inspect population observations.

Population by year

Population estimates for New Castle. Annual change is shown as a percentage. Growth is the total change since the preceding observation.
20265,766+400.70%
20255,726+270.47%
20245,699+1212.17%
20235,578+450.81%
20225,533+150.27%
20215,518-330.59%
20205,551-80.14%
20195,559+571.04%
20185,502+2384.52%
20175,264-30.06%

Showing 10 of 33 years.

The 2020 row compares the April 1 Census count with the July 1, 2019 estimate (about nine months). Its Growth and Annual change therefore do not represent a full year.

Growth since 2020, compared

New Castle is growing faster than New Castle County and the U.S., and slower than Delaware.

  • Delaware+6.9%
  • New Castle+3.4%
  • United States+3.1%
  • New Castle County+3.0%

Change from July 1, 2020 to July 1, 2025 population estimates—not annualized growth or site projections.

Source: U.S. Census Bureau. U.S. totals are summed from the 50 states and D.C.; unavailable comparisons are omitted.

New Castle Demographics

48.5median age

Median age

Female49.8 yrs
Male43.8 yrs

Adults

4,664
1,279 seniors (65+) · 27% of adults3,385 other adults

Sex

Female 52% · 2,902Male 48% · 2,677

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S0101

Race and ethnicity

Tap a square or a group below to highlight it.

Each square is about 1% of residents (roughly 56 people).

Hispanic or Latino residents can be of any race. All other groups exclude Hispanic residents.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table B03002

New Castle Income

$89,205median household income

Median household income

$89,205

Half of households earn more, half earn less

Median earnings

$58,931

Typical yearly pay for a worker 25 or older.

Poverty rate

4.7%

About 1 in 21 residents

U.S. Census Bureau, 2024 ACS 5-year estimates · Tables S1901, S1501, S1701

New Castle Marital Status

46% of residents age 15 and older are married.

MarriedNever married
Overall
Male
Female
Marital status of residents age 15 and older
StatusOverallMaleFemale
Married46%52%40%
Never married31%37%27%
Divorced15%9%21%
Widowed7%3%10%
Separated1%<1%2%

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S1201