May we count your visit with Google Analytics? It uses cookies and sends visit data to Google. You can change this any time under Cookie choices. Privacy

Where am ILOCATED

New Castle County, Delaware

New Castle County, Delaware, has 588,026 residents (July 2025 estimate). Its county seat is Wilmington. It uses Eastern Time and covers 426 sq mi (1,104 km²) of land.

WilmingtonDoverNewark
New Castle County in Delaware
Cecil CountyGloucester CountySalem CountyWilmingtonNewarkMiddletownBearGlasgow
New Castle County and its neighbors (simplified outlines). Open in OpenStreetMap ↗
Resident population, July 2025
588,026
Land area
426 sq mi (1,104 km²)
County seat or government
Wilmington
Time zone
Eastern TimeUTC-05:00 in January; UTC-04:00 in July
Median household income
$91,166 ± $1,765
Median home value
$352,200 ± $3,776
Median rent, with utilities
$1,448 ± $22
Homes lived in by their owners
69% ± 0.8 points
County type
County
Metro or micro area
Philadelphia-Camden-Wilmington, PA-NJ-DE-MD metro areaCentral county
Water area
67.7 sq mi (175 km²)
State
Delaware
County code (FIPS)
10003
Coordinates (central point)
39.575915, -75.644132
Open this point in the location finder

These coordinates mark a central point for the area, not a street address. Income, home value, rent and homes lived in by their owners: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, ± margin at 90% confidence; checked on October 13, 2026.

Time zones in New Castle County

Time zoneLocal time and UTC offsetNext clock change
Eastern TimeAmerica/New_YorkUTC-05:00 in January; UTC-04:00 in July. Enable JavaScript for the live clock.Enable JavaScript for upcoming changes.

Near a time-zone line, check where you are with the time-zone finder. Your phone’s setting can differ.

ZIP Code areas, largest first

  1. 1972062,392 people
  2. 1970255,683 people
  3. 1970953,234 people
  4. 1971149,432 people
  5. 1970142,984 people
  6. 1980541,402 people
  7. 1980839,082 people
  8. 1971330,747 people
  9. 1997727,704 people
  10. 1981026,530 people
  11. 1980226,051 people
  12. 1980322,279 people
All 32
  1. 1980418,779 people
  2. 1970717,376 people
  3. 1980116,327 people
  4. 1970315,460 people
  5. 1980914,311 people
  6. 1973414,214 people
  7. 198069,777 people
  8. 199389,561 people
  9. 198077,815 people
  10. 197176,036 people
  11. 197062,038 people
  12. 219121,536 people
  13. 19731655 people
  14. 19730425 people
  15. 19733186 people
  16. 19736127 people
  17. 1973289 people
  18. 197100 people
  19. 197160 people
  20. 197350 people

32 ZIP Code areas overlap New Castle County. People counts are 2020–2024 estimates for each whole ZIP area. Mailing ZIPs can differ; check an address with USPS ZIP Code Lookup.

Official county information

We don’t have a website for this county yet. The US government’s local-office directory ↗ lists its offices. A geographic lookup cannot determine eligibility, tax liability or a court obligation.

School districts in New Castle County, largest first

  1. Christina School District176,766 people
  2. Red Clay Consolidated School District139,682 people
  3. Brandywine School District92,908 people
  4. Colonial School District90,439 people
  5. Appoquinimink School District72,684 people
  6. Smyrna School District40,677 people

Districts with land in the county; a district can cross county lines. People counts are American Community Survey 2020–2024 5-year estimates. A district boundary doesn’t decide which school a student attends.

Cities, towns and communities, largest first

These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.

  1. Wilmington, Delaware (city)71,727 people
  2. Newark, Delaware (city)30,330 people
  3. Middletown, Delaware (town)24,661 people
  4. Bear, Delaware (CDP)22,370 people
  5. Glasgow, Delaware (CDP)15,546 people
  6. Brookside, Delaware (CDP)15,115 people
  7. Hockessin, Delaware (CDP)13,439 people
  8. Smyrna, Delaware (town)13,165 people
  9. Pike Creek Valley, Delaware (CDP)12,431 people
  10. Claymont, Delaware (CDP)8,786 people
  11. Wilmington Manor, Delaware (CDP)8,214 people
  12. North Star, Delaware (CDP)7,834 people
All 28
  1. Pike Creek, Delaware (CDP)7,129 people
  2. Edgemoor, Delaware (CDP)6,349 people
  3. Elsmere, Delaware (town)6,203 people
  4. New Castle, Delaware (city)5,579 people
  5. Clayton, Delaware (town)4,222 people
  6. Greenville, Delaware (CDP)3,713 people
  7. Townsend, Delaware (town)2,832 people
  8. Delaware City, Delaware (city)1,950 people
  9. St. Georges, Delaware (CDP)1,530 people
  10. Bellefonte, Delaware (town)1,388 people
  11. Newport, Delaware (town)900 people
  12. Arden, Delaware (village)627 people
  13. Port Penn, Delaware (CDP)592 people
  14. Odessa, Delaware (town)409 people
  15. Ardentown, Delaware (village)233 people
  16. Ardencroft, Delaware (village)213 people

Bordering areas, nearest first

Distances are straight lines between map points.

  1. Salem County, New Jersey15 mi east
  2. Cecil County, Maryland16 mi west
  3. Delaware County, Pennsylvania27 mi northeast
  4. Chester County, Pennsylvania28 mi north
  5. Gloucester County, New Jersey28 mi east
  6. Kent County, Delaware34 mi south

Before using this answer on a form

Use a precise point for address-level questions. A device accuracy circle can cross a boundary; confirm tax, voting or jury details with the responsible office.

Find the county where you are now, check its ZIP area, or check the time zone where you are.

See this county on Census.gov ↗

Areas that only touch the edge

These areas meet the boundary only along a sliver. Most addresses here are not in them; for an address near the line, check with the county.