Middlesex County, NJ vs Richmond County, NY

Neighbouring counties across the New Jersey and New York state line, compared on population, size, income and housing. They share 11 mi of border.

Both outlines are drawn at true relative size. Middlesex County spans about 43.4 km at its widest.

Side by side

Middlesex County, New Jersey and Richmond County, New York on shared measures. The middle column is the difference, computed from the two figures either side of it.
MeasureMiddlesex CountyDifferenceRichmond County
Population883,335+76.2%501,290
Change since 20202.6%+1.4 pp1.2%
Land area309.3 sq mi+437.7%57.5 sq mi
Population density2,856 per sq mi-67.2%8,715 per sq mi
Median household income$111,549+13.4%$98,333
Median home value$462,900-31.5%$675,500
Median age39.5-2.7%40.6
Households307,782+80.2%170,777
Housing units317,979+72.2%184,621

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026; US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. The difference column is computed here: the first county's figure against the second, expressed as a percentage of the second. The change-since-2020 row is the exception: two growth rates differ in percentage points (pp), not percent. Retrieved 30 August 2026.

What the numbers say

  • Middlesex County holds about 1.8 times the population of Richmond County: 883,335 against 501,290.
  • Middlesex County covers more ground, at 309.3 square miles against 57.5.
  • Richmond County is the more crowded of the two, at 8,715 people per square mile against 2,856.
  • Median household income is higher in Middlesex County, by 13,216 dollars a year.
  • Since 2020, Middlesex County has grown by 2.6% and Richmond County has grown by 1.2%.
  • They share 11 mi of common border, which the Census Bureau publishes in its county adjacency file and which almost no other county reference presents.

Full pages

Want a different pair? Compare any two of the 3,144 US counties.

Rebuilt from source data 30 August 2026. How these figures are produced.