Mercer County, New Jersey
Mercer County, New Jersey
| Census | Population |
|---|---|
| 2000 | 350,761 |
| 2010 | 366,513 |
| 2020 | 387,340 |
As counted at each census, within the boundaries the area had then; the current estimate is in the glance card.
Sources: Census 2000 Summary File 1: total population, county level, state 34, retrieved November 14, 2026; Census 2010 Summary File 1: total population, county level, state 34, retrieved November 14, 2026; Census 2020 Redistricting Data (P.L. 94-171): total population, county level, state 34, retrieved November 14, 2026.
| Measure | Mercer County | New Jersey |
|---|---|---|
| Population | 383,286 | 9,267,014 |
| Median household income | $96,333 | $101,050 |
| Median age | 39.2 | 40.1 |
| Median home value | $351,000 | $427,600 |
| Bachelor’s degree or higher | 44.9% | 42.9% |
| Foreign-born residents | 25.7% | 23.5% |
| Owner-occupied homes | 61.9% | 63.7% |
| Mean commute to work | 27.6 minutes | 30.9 minutes |
Source: American Community Survey 5-year data profile 2019–2023, county level, state 34, retrieved November 14, 2026.
Median household income $96,333 · Share of households by income, American Community Survey 5-year 2019-2023, table S1901.
Source: American Community Survey 5-year subject table S1901 (household income) 2019–2023, county level, state 34, retrieved November 14, 2026.
- Owner occupied
- 87,554 units
- Renter occupied
- 53,910 units
- Vacancy rate
- 6.1%
Occupied housing units by tenure and the share of all units vacant, American Community Survey 5-year 2019-2023, table DP04.
Source: American Community Survey 5-year data profile 2019–2023, county level, state 34, retrieved November 14, 2026.
208,192 employees in 9,683 establishments with payroll in 2023, all sectors; employers themselves are not named in the source. County Business Patterns counts are published with noise.
Source: County Business Patterns 2023: employment by sector, county level, state 34, retrieved November 14, 2026.
Townships, towns and villages in Mercer County
- East Windsor TownshipTownship
- Ewing TownshipTownship
- GrovevilleCensus designated place
- Hamilton TownshipTownship
- Hamilton SquareCensus designated place
- HightstownBorough
- Hopewell TownshipTownship
- HopewellBorough
- Lawrence TownshipTownship
- LawrencevilleCensus designated place
- MercervilleCensus designated place
- PenningtonBorough
- Princeton JunctionCensus designated place
- Robbinsville TownshipTownship
- Robbinsville CenterCensus designated place
- The College of New JerseyCensus designated place
- TitusvilleCensus designated place
- TrentonCity
- Twin RiversCensus designated place
- Washington CrossingCensus designated place
- West Windsor TownshipTownship
- White HorseCensus designated place
- WindsorCensus designated place
- YardvilleCensus designated place
Neighboring counties
- Bucks County, PANo page yet
- Burlington CountyPopulation 475,515 (2024 estimate)
- Hunterdon CountyPopulation 131,708 (2024 estimate)
- Middlesex CountyPopulation 890,119 (2024 estimate)
- Monmouth CountyPopulation 647,520 (2024 estimate)
- Somerset CountyPopulation 357,467 (2024 estimate)
Sources: Census county adjacency file 2024, retrieved November 14, 2026; Census Population Estimates, Vintage 2024: subcounty totals, state 34, retrieved November 14, 2026.
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- Type
- County
- Land area
- 224.5 sq mi
- Water area
- 4.37 sq mi
- Population
- 392,138 (2024 estimate)
- Households
- 141,464
- Median age
- 39.2
- Median household income
- $96,333
- Median home value
- $351,000
- Median gross rent
- $1,515
- Owner-occupied homes
- 61.9%
- Bachelor’s degree or higher
- 44.9%
- Foreign-born residents
- 25.7%
- Mean commute to work
- 27.6 minutes
- Census GEOID
- 34021
Sources: Census Gazetteer 2025: counties, retrieved November 14, 2026; Census Population Estimates, Vintage 2024: subcounty totals, state 34, retrieved November 14, 2026; American Community Survey 5-year data profile 2019–2023, county level, state 34, retrieved November 14, 2026.
- ZIP codes
- 08512, 08520, 08525, 08530, 08534, 08540, 08542, 08544, 08550, 08560, 08561, 08608, 08609, 08610, 08611, 08618, 08619, 08620, 08628, 08629, 08638, 08648, 08690, 08691
- Metro area
- Trenton-Princeton, NJ
Sources: Census 2020 ZCTA relationship file: ZCTAs to counties, retrieved November 14, 2026; Census Gazetteer 2025: metropolitan and micropolitan areas, retrieved November 14, 2026.