- county
- FIPS 34023
- Largest town: New Brunswick
Middlesex County, New Jersey
Middlesex County had 890,119 residents in the Census Vintage 2024 estimate, on 309.3 square miles of land. It ranks 2nd of 21 in New Jersey by population and 12th by land area.
- Population
- 890,119
- #2 of 21 in New Jersey · #66 in US
- Area
- 309.3 sq mi
- #12 of 21 in New Jersey · #2,787 in US
- Density
- 2,878 / sq mi
- #5 of 21 in New Jersey · #41 in US
- Median household income
- $104,637
- #7 of 21 in New Jersey · #92 in US
Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area
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Middlesex County population, land area and income
Middlesex County had 890,119 residents in the Census Vintage 2024 estimate, on 309.3 square miles of land. It ranks 2nd of 21 in New Jersey by population and 12th by land area. That works out to 2,878.3 people per square mile, 29.9 times the US average of 96.3, and in the top tenth nationally.
The median county-equivalent in New Jersey has 475,515 residents; Middlesex County is somewhat larger.
Its SAIPE 2023 median household income of $104,637 is in the top tenth among 3,143 counties with an estimate.
National rank among 3,144
Population
890,119
66th of 3,144 (US)
Land area
309 sq mi
2787th of 3,144 (US)
Density
2,878.3 / sq mi
41st of 3,144 (US)
Median household income
$104,637
92nd of 3,143 (US)
Rank within New Jersey (21)
Population
890,119
2nd of 21 (NJ)
Land area
309 sq mi
12th of 21 (NJ)
Density
2,878.3 / sq mi
5th of 21 (NJ)
Median household income
$104,637
7th of 21 (NJ)
How Middlesex County's population changed since 2020
Middlesex County gained 28,659 residents between the July 2020 and July 2024 estimates, a rise of 3.3%. That ranks 4th of 21 in New Jersey for growth. The median New Jersey county changed by +2.3%, and the state as a whole by +2.5%.
Since the April 2020 estimates base, Middlesex County recorded 36,360 births and 28,485 deaths, a natural change of +7,875. Net international migration added +45,074 and net domestic migration, people moving to or from other US counties, came to -26,850. The largest single component was international migration, which added 45,074 people.
Components of change, April 2020 to July 2024
- Births
- 36,360
- Deaths
- 28,485
- Net international migration
- +45,074
- Net domestic migration
- -26,850
- Change, July 2023 to July 2024
- +14,000
Where Middlesex County is
The Census internal point of Middlesex County is at 40.439600, -74.407400. It sits in UTM zone 18N. The map shades New Jersey's 21 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Middlesex County outlined. Dots are towns of 1,000+ people with residents in it.
- < +1.5%
- < +2.1%
- < +2.5%
- < +3.0%
- ≥ +3.0%
Orange pin: Middlesex County internal point. Dark pin: Trenton.
Internal point
- Decimal
- 40.439600, -74.407400
- DMS
- 40°26'22.56"N 74°24'26.64"W
- UTM
- 18N 550258.4E 4476719.0N
- Geohash
- dr5n4cf1t
- Plus code
- 87G7CHQV+R2
Towns in Middlesex County
15 incorporated places of 1,000+ people have residents in Middlesex County, 317,587 people together, or 36% of the county. Each figure counts only the part of the town inside Middlesex County; towns marked "part" extend into another county. The largest is New Brunswick with 57,487.
- 01New Brunswick57,487
- 02Perth Amboy56,939
- 03Sayreville47,165
- 04Carteret26,003
- 05South Plainfield25,062
- 06South River16,392
- 07Metuchen15,470
- 08Highland Park15,386
- 09Middlesex14,874
- 10South Amboy10,549
- 11Dunellen8,411
- 12Spotswood8,306
- 13Milltown7,170
- 14Jamesburg5,869
- 15Helmetta2,504
Counties bordering Middlesex County
The Census 2024 county adjacency file lists 5 neighbors for Middlesex County, including 1 across a state line. The most populous is Monmouth County, NJ, with 647,520 residents. Distances run between Census internal points in a straight line.
Distance to Trenton and the nearest big city
Trenton is 23.8 miles SW of Middlesex County's internal point in a straight line. The nearest place of 100,000 or more is Elizabeth, NJ (population 140,413), 19.3 miles away. The nearest place of 10,000 or more is South River, NJ (population 16,392), 1.6 miles away.
Middlesex County FIPS code
The FIPS code of Middlesex County is 34023: state code 34 for New Jersey plus county code 023. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $104,637.
Questions people ask
What is the population of Middlesex County, New Jersey?
The Census Vintage 2024 estimate for July 1, 2024 is 890,119. That is up 28,659 people (3.3%) from the July 2020 estimate of 861,460.
What is the FIPS code of Middlesex County?
34023. The first two digits (34) are New Jersey; the last three (023) identify the county.
What is the largest town in Middlesex County?
New Brunswick, with 57,487 residents inside Middlesex County in 2024.
Which counties border Middlesex County?
5 county-equivalents border it in the Census 2024 adjacency file: Monmouth County, NJ; Union County, NJ; Richmond County, NY; Mercer County, NJ; Somerset County, NJ.
Sources and data as of
Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.
- 01Census Vintage 2024 county population estimates
- 02Census 2024 Gazetteer, counties
- 03Census SAIPE 2023 state and county estimates
- 04Census Vintage 2024 subcounty population estimates
- 05Census 2024 county adjacency file
- 06Census 2024 cartographic boundary file, counties (1:5,000,000)
How every number is computed: methodology. Spotted a wrong figure? Report an error.