Mercer County, New Jersey
Located in New Jersey, Mercer County has a population of 385,864 residents and a median age of 39.5 years, making it the #193 most populous county out of 3,222 nationwide. In terms of economic indicators, the county has a poverty rate of 10.3%. The median home value is $377,700, and the median household income is $100,645, which is 34% above the national median.
Demographics
Mercer County has a population of 385,864, making it the #193 most populous county in the US. The median age is 39.5 years, which is 1.5% above the national median.
Population Trend
Rankings →Year-over-Year Population Growth
Age & Sex Distribution
Race & Ethnicity
Nativity
Geographic Mobility (Past Year)
Economy
The median household income in Mercer County is $100,645, ranking #166 out of 3,222 counties — 33.9% above the national median. The poverty rate is 10.3% and unemployment stands at 6.3%.
Median Household Income Trend
Rankings →Income Distribution
Industry of Employment
Occupation
Housing
The median home value in Mercer County is $377,700 (+34.0% vs national). Renters pay a median of $1,623/mo and the homeownership rate is 62.2%.
Median Home Value Trend
Rankings →Household Type
Education
In Mercer County, 45.4% of adults age 25+ hold a bachelor's degree or higher, which is 34.8% above the national average, ranking #167 out of 3,222 counties.
Bachelor's Degree or Higher Trend
Rankings →Health & Wellbeing
Life expectancy in Mercer County is 78.4 years. 14.8% of adults report poor or fair health and 8.7% lack health insurance. Data from County Health Rankings (2025).
Life Expectancy Trend
Substance Use
10.4% of adults in Mercer County smoke , 30.7% are obese , and 17.4% report excessive drinking. The drug overdose death rate is 35.4 per 100,000.
Adult Smoking Trend
Safety
The homicide rate in Mercer County is 8.3 per 100,000 and the suicide rate is 7.2 per 100,000. Motor vehicle deaths occur at a rate of 7.0 per 100,000.
Homicide Rate Trend
Families & Children
13.1% of children in Mercer County live in poverty and the infant mortality rate is 5.1 per 1,000 live births. The teen birth rate is 13.7 per 1,000 females age 15–19.
Infant Mortality Trend
Civic & Transportation
Voter turnout in Mercer County is 70.4%. The mean commute time is 29.7 min, which is 7.6% above the national average.
Voter Turnout Trend
Mean Commute Time Trend
Rankings →Elections
In the 2024 presidential election, Mercer County voted Democratic with a margin of 33.9%. The vote was 65.9% Dem / 32% Rep. Compared to 2020, the margin shifted 6.1 toward Republicans .
Vote Share Over Time
About Mercer County, New Jersey
Mercer County, New Jersey has a total population of 385,864, making it the 193rd most populous county in the United States. The median age in Mercer County is 39.5 years, which is 1.5% above the national median of 38.9 years.
The median household income in Mercer County is $100,645, which ranks #166 of 3,222 counties nationwide. This is 33.9% above the national median of $75,149. The poverty rate is 10.3%, lower than the national rate of 12.6%. The unemployment rate stands at 6.3%.
The median home value in Mercer County is $377,700, 34.0% above the national median. Renters in Mercer County pay a median gross rent of $1,623 per month. The homeownership rate is 62.2%, compared to the national rate of 64.4%.
In Mercer County, 45.4% of residents aged 25 and older hold a bachelor's degree or higher, 34.8% above the national average of 33.7%. Health insurance coverage stands at 92.1% of the population. The average commute time for workers is 29.7 min.
Mercer County is a diverse community. The largest racial or ethnic group is White (non-Hispanic) at 42.7% of the population, followed by Hispanic or Latino (23.1%) and Black (non-Hispanic) (17.9%).
All data for Mercer County, New Jersey comes from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates. These figures are estimates based on survey sampling and are subject to margin of error. For the most detailed and up-to-date data, visit the Census Bureau's official data portal.