Mercer County, New Jersey Demographics
Population trends, housing costs, income, commuting, and health, all on one page.
Mercer County, NJ Population Density Map and Area Scores
Area Score
Health, income and education, each graded from F to A+. Explore interactive maps for deeper analysis.
-
B
Health Around average
-
B
Income Around average
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A
Education Above averageBetter educated than 75% of counties in New Jersey
Source: Map AI Methodology
Population: density and quick facts
| Metric | Mercer County | New Jersey Avg | U.S. Average |
|---|---|---|---|
| Population | 385,681 | 9,334,304 | 337,468,954 |
| Population density (per sq mi) | 1686.6 | 1071.4 | 86.4 |
| Population growth (%/yr) | 0.46% | 0.59% | 0.59% |
| Median age | 38.1 | 40.2 | 37.3 |
| Households | 143,869 | 3,503,323 | 130,235,071 |
Population in Mercer County grew by 5.8% from 2009 to 2024, reaching 385,681 in 2024.
Population Growth 2009–2024
Race & Ethnicity
Age & Sex
The largest generation in Mercer County is Gen Z, aged 13–28, at 22.1% of residents. That is 2.0 points above New Jersey as a whole.
- Gen Z 13–28 85,333 22.1% +2.0 pts
- Millennials 29–44 81,002 21.0% -0.8 pts
- Gen X 45–60 81,989 21.3% -0.2 pts
- Boomers 61–79 61,501 15.9% -0.9 pts
Residents by birth cohort, from the 2025 age distribution. The right-hand figure is how far each cohort's share sits above or below New Jersey, in percentage points. Children younger than Gen Z and the generations before the Boomers are counted in the population but not shown here, so these shares do not add up to 100%.
Male and female share
Women are 50.6% of the people living in Mercer County and men 49.4%.
- Women 50.6% New Jersey 50.9%
- Men 49.4% New Jersey 49.1%
How many residents match a customer profile?
Residents matching this profile
100% of everyone living in Mercer County
Pick an age range and a women/men split and the figure above answers with how many residents that profile reaches.
Economy
Mercer County has a the economy index of B, which means it is quite prosperous.
| Metric | Mercer County | New Jersey Avg | U.S. Average |
|---|---|---|---|
| Median household income | $100,788 | $103,817 | $80,455 |
| Income growth (%/yr) | 3.94% | 4.37% | 4.80% |
| Unemployment rate | 6.3% | 6.3% | 5.2% |
The median household income in Mercer County is about 3% lower than in New Jersey.
Housing
| Metric | Mercer County | New Jersey Avg | U.S. Average |
|---|---|---|---|
| Median home price | $246,616 | $352,792 | $248,835 |
| Median rent | $1,622 | $1,719 | $1,407 |
| Homeownership rate | 62.2% | 63.8% | 65.2% |
The median home price in Mercer County is about 12.7 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $1,622 per month for that long.
Commute Time & Mobility
Commuters in Mercer County spend about 43 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 180 hours, about 7.5 full days, spent commuting.
| Metric | Mercer County | New Jersey Avg | U.S. Average |
|---|---|---|---|
| One-way commute (min) | 21.7 | 26.2 | 22.4 |
| Round-trip commute (min) | 43.3 | 52.4 | 44.8 |
| Yearly time spent (hours) | 180 | 218 | 187 |
| Estimated yearly cost | $5,593 | $6,764 | $5,790 |
| Work from home | 19.5% | 16.8% | 15.0% |
| Highway traffic (vehicles/day) | 10,045 | 14,317 | 8,813 |
| Local road traffic (vehicles/day) | 1,555 | 2,109 | 1,355 |
Fastest commutes among counties in
New Jersey:
Cape May County (18.1 min), Cumberland County (21.2 min), Atlantic County (21.6 min).
Slowest:
Hudson County (32.7 min), Sussex County (32.6 min), Hunterdon County (31.0 min).
The average commute time in Mercer County is 22 minutes, shorter than the 26 minutes in New Jersey.
Estimated yearly cost applies a single national wage rule of thumb (U.S. Bureau of Labor Statistics average hourly earnings), not a measurement of wages in this area. Traffic volume figures come from proprietary Ticon and TrafficZoom data.
Education & Households
Mercer County has a education index of A, which means it is very educated.
| Metric | Mercer County | New Jersey Avg | U.S. Average |
|---|---|---|---|
| Bachelor's degree or higher | 40.1% | 39.6% | 31.6% |
| Average household size | 2.56 | 2.61 | 2.53 |
Highest education index among counties in
New Jersey:
Somerset County (0.4), Morris County (0.4), Hunterdon County (0.4).
Lowest:
Cumberland County (0.2), Salem County (0.2), Passaic County (0.3).
Health
Mercer County has a health index of B, which means it is quite healthy.
| Metric | Mercer County | New Jersey Avg | U.S. Average |
|---|---|---|---|
| Life expectancy (years) | 78.9 | 79.4 | 78.3 |
| Self-rated poor health | 14.2% | 12.9% | 16.3% |
| Smokers | 15.3% | 14.2% | 19.0% |
Highest health index among counties in
New Jersey:
Morris County (0.8), Hunterdon County (0.8), Somerset County (0.8).
Lowest:
Cumberland County (0.8), Salem County (0.8), Passaic County (0.8).
Mercer County, NJ Compared With Nearby Counties
Mercer County, NJ is the 4th largest of the 6 counties compared here, 385,681 residents against a local median of 467,571. Where Mercer County, NJ breaks from the counties next to it is commute, sitting 19% below the local median of 26.6 min at 21.7 min. That is the better end of the local range on this measure.
The counties themselves spread 7.2 min on commute, so Mercer County, NJ sits at one end of an already wide local range rather than apart from it. Mercer County, NJ has the lowest commute of the 6 areas compared here.
| Area | Population | Median household income | Median home price | Commute |
|---|---|---|---|---|
| Mercer County, NJ | 385,681 | $100,788 #6/6 | $246,616 #6/6 | 21.7 min #1/6 |
| Somerset County, NJ | 349,714 | $140,426 | $304,018 | 26.9 min |
| Middlesex County, NJ | 870,701 | $112,064 | $279,129 | 26.6 min |
| Hunterdon County, NJ | 130,145 | $142,458 | $292,762 | 31.0 min |
| Burlington County, NJ | 467,571 | $108,527 | $248,885 | 26.0 min |
| Bucks County, PA | 647,283 | $115,660 | $248,394 | 23.8 min |
Frequently Asked Questions
Common questions about Mercer County, New Jersey.
What is the population of Mercer County, New Jersey?
About 385,681 people live in Mercer County, New Jersey, in 143,869 households of 2.6 people on average. The median age is 38.1, close to the U.S. median of 37.3.
How densely populated is Mercer County, New Jersey?
Averaged over its land area, Mercer County, New Jersey has 1,687 people per square mile, a density typical of urban and suburban areas. That is about 20 times the U.S. average of 86.
Can a typical household afford a home in Mercer County, New Jersey?
The median home costs 2.4 times the median household income ($246,616 against $100,788), compared with 3.1 times nationally. That is within the traditional rule of thumb of about 3 times income. Median rent of $1,622 a month takes about 19% of the median household's income, below the 30% level at which HUD considers renters cost-burdened.
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