Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — RANKINGS/DE/LARGEST-POPULATION

ZIP Codes With the Largest Population in Delaware

What this measures. Population of the Census tabulation area, ACS 5-year estimate. Source: Census American Community Survey, data release 2026-10-12.

# ZIP City County Population
1 19720 New Castle New Castle 62,392
2 19702 Newark New Castle 55,683
3 19709 Middletown New Castle 53,234
4 19711 Newark New Castle 49,432
5 19701 Bear New Castle 42,984
6 19805 Wilmington New Castle 41,402
7 19808 Wilmington New Castle 39,082
8 19904 Dover Kent 38,818
9 19901 Dover Kent 37,763
10 19966 Millsboro Sussex 35,884
11 19958 Lewes Sussex 31,938
12 19713 Newark New Castle 30,747
13 19977 Smyrna Kent 27,704
14 19973 Seaford Sussex 26,834
15 19810 Wilmington New Castle 26,530
16 19802 Wilmington New Castle 26,051
17 19963 Milford Sussex 23,500
18 19803 Wilmington New Castle 22,279
19 19947 Georgetown Sussex 20,760
20 19804 Wilmington New Castle 18,779
21 19707 Hockessin New Castle 17,376
22 19801 Wilmington New Castle 16,327
23 19956 Laurel Sussex 16,327
24 19968 Milton Sussex 15,486
25 19703 Claymont New Castle 15,460
26 19971 Rehoboth Beach Sussex 14,886
27 19809 Wilmington New Castle 14,311
28 19734 Townsend New Castle 14,214
29 19934 Camden Wyoming Kent 14,061
30 19962 Magnolia Kent 13,770
31 19943 Felton Kent 13,410
32 19952 Harrington Kent 10,908
33 19975 Selbyville Sussex 10,862
34 19933 Bridgeville Sussex 10,597
35 19806 Wilmington New Castle 9,777
36 19945 Frankford Sussex 9,640
37 19938 Clayton Kent 9,561
38 19970 Ocean View Sussex 8,524
39 19950 Greenwood Sussex 7,918
40 19807 Wilmington New Castle 7,815
41 19940 Delmar Sussex 7,540
42 19939 Dagsboro Sussex 7,490
43 19960 Lincoln Sussex 6,774
44 19717 Newark New Castle 6,036
45 19946 Frederica Kent 5,603
46 19953 Hartly Kent 5,255
47 19941 Ellendale Sussex 3,435
48 19930 Bethany Beach Sussex 3,014
49 19967 Millville Sussex 2,376
50 19951 Harbeson Sussex 2,245

Showing the top 50 of 68 ZIP codes in Delaware that have this figure . 19720 ranks 1st at 62,392, against 2,245 in 50th place.

Other rankings for Delaware

Cite this page

zipcodes.pro. “ZIP Codes With the Largest Population in Delaware.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/rankings/de/largest-population

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