New Castle: Demographics & People

New Castle's population stands at 5,579 people, in 2,774 households. Population grew 1.1% from 5,519 (2022) to 5,579 (2024). Median age 48.5 years. (9.2y older than New Castle County; 11.5y older than Delaware). Children under 18 are 16% of the population. Population is 60% White (non-Hispanic) and 28% Black. The community is moderately diverse (Simpson index 0.49). 55% of households are family-led. County is gaining 1,395 residents per year (2022-2023). County health: 38% adult obesity, 14% smoke.

Population & Trend

Population grew 1.1% from 5,519 (2022) to 5,579 (2024) — about 1.8× the recent U.S. annual rate of ~0.6%/yr. Estimated 2026 population: ~5,639 (extrapolated at 0.5%/yr trend). Census Bureau Vintage estimate: 5,722.

Census data vintage2024
Population570,719 people
Annual growth rate · Population change1.1%
Annual growth rate · Population (2022)5,519
Annual growth rate · Population (2024)5,579
Annual growth rate · Population growingYes
Annual growth rate · Trend categorygrowing
Population5,579 people (vs Delaware 13,439) population: 6 observations from 2026-04-17 to 2026-04-29
Population Estimate5,722

Sources: Census ACS 5-Year 2023, Table B01003  ·  Refreshed 2026-04-12

Age Distribution

Median age 48.5y is 9.6 years older than the U.S. median (38.9y). Children under 18 make up 16% — below the U.S. share of ~22%.

Age Summary · Median age48.5 years (vs Delaware 37.0y)
Age Summary · Children Pct16.4%
Age Summary · Characterestablished
Age Summary · Total Pop5,579
Age Summary · Under 18915
Age Summary · 18 To 34974.0×
Age Summary · 35 To 642,411.0×
Age Summary · 65 Plus1,279
Population under 18915
Median age48.5 years (vs Delaware 37.0y)

Sources: Census ACS 5-Year 2024 — place-level B01001 query · Census ACS 5-Year 2023  ·  Refreshed 2026-04-29

Race, Ethnicity & Diversity

Of 5,579 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.49 (0 = single group, 1 = perfectly even distribution); this is read as moderately diverse.

White residents3,574
Black residents1,532
Asian residents49
Hispanic or Latino residents288
Diversity Index · Diversity index (Simpson)48.7%
Diversity Index · Diversity labelmoderately diverse
Diversity Index · Groups counted4
Diversity Index · Largest group share65.7%
Asian population0.9% (vs Delaware 2.9%)
Black population28.4% (vs Delaware 26.7%)
Hispanic or Latino population8.1% (vs Delaware 10.7%)
White (non-Hispanic) population60.4% (vs Delaware 51.8%)

Sources: Census ACS 5-Year 2023  ·  Refreshed 2026-04-12

Ancestry

Self-reported ancestry from Census ACS — what residents report as their ethnic origin, separate from race. Counts can exceed population because people can list multiple ancestries.

Top (8)

(unnamed)
Black
(unnamed)
English
(unnamed)
Irish
(unnamed)
German
(unnamed)
Polish
(unnamed)
Italian
(unnamed)
Hispanic Total
(unnamed)
Puerto Rican

Citizenship & Origin

Where residents were born and their citizenship status (Census ACS).

Residents born in this state2,718
Residents born in another state2,299
Share born in this state48.7%
Share born in another state51.3%
Total foreign-born residents348
From Europe162
From Africa13

Households & Family Composition

2,774 households. Averaging 2.0 people each — smaller than the U.S. average of 2.5. 55% are family households — below the U.S. share of ~65%. Of 1,597 families, 21% are married couples with children.

Children under 18910
Total families1,597
Married couples with children335
Single-parent households71
Average household size2.04
Women who gave birth (past year)20.9%
Grandparents living with grandchildren147
Grandparents responsible for grandchildren61
Family households1,530 households (vs Delaware 3,428)
Households that are families55.2% (vs Delaware 58.6%)
Total households2,774 households (vs Delaware 5,560) total_households: 4 observations from 2026-04-23 to 2026-04-29

Sources: Census ACS 5-Year 2023  ·  Refreshed 2026-04-12

Residential Stability & Migration

How long residents have lived here and where they came from. 11.3% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is gaining 1,395 residents per year on net (IRS migration data).

Moved within the county (past year)11.3%
Migration · People moving in (annual)500,294
Migration · People moving out (annual)498,899
Migration · Net migration (in − out)1,395
Migration · Population growingYes
Migration · Year2022-2023

Sources: IRS SOI Migration 2021-2022  ·  Refreshed 2026-04-12

Disability

Census ACS measures self-reported functional limitations — vision, hearing, mobility, cognitive, self-care, or independent-living. The U.S. baseline disability rate is about 12–13%; rates trend higher with median age.

Residents with a disability333
Disability rate6.1%

Group Quarters

Group quarters are non-household living arrangements counted by the Census — college dormitories, nursing homes, military barracks, group homes, correctional facilities, and similar institutional or shared housing. 3 residents live in group quarters (0.1% of population).

Living in group quarters3

Other

Congressional District · Congress118th
Cdc Birth Rate · Fips10003
Cdc Birth Rate · State Fips10
Cdc Birth Rate · County Fips003
Cdc Birth Rate · CountyNew Castle
Cdc Birth Rate · Birth Rate12.4%
Cdc Birth Rate · Lower Ci11.50
Cdc Birth Rate · Upper Ci13.20
Cdc Mortality · Fips10003
Cdc Mortality · CountyNew Castle County
Cdc Mortality · Urban RuralLarge fringe metro
Cdc Mortality · Total Deaths 2020 202321,207
Cdc Vaccination · Fips10003
Cdc Vaccination · CountyNew Castle County
Cdc Vaccination · Dose1 Pop Pct89.4%
Cdc Vaccination · Series Complete Pct73.6%
Cdc Vaccination · Booster Pct51.1%
Cdc Vaccination · Population 2019558,753
Cdc Vaccination · Metro StatusMetro
Family Score · Score10
Family Score · Schools15
Family Score · Childcare Centers15
Family Score · Youth Sports Orgs2
Family Score · Children Pct16.4%
Family Score · Ratingexcellent
Town Summary · Key Factspopulation 5,579, growing, established, upper-middle, white collar
Town Summary · Population5,579 people (vs Delaware 13,439)
Town Summary · CountyNew Castle County

Sources: NCES school congressional district assignment · federal dataset cascade