Merrimack County, New Hampshire
Located in New Hampshire, Merrimack County has a population of 155,967 residents and a median age of 42.9 years, making it the #446 most populous county out of 3,222 nationwide. In terms of economic indicators, the county has a poverty rate of 7.6%. The median home value is $367,600, and the median household income is $97,004, which is 29% above the national median.
Demographics
Merrimack County has a population of 155,967, making it the #446 most populous county in the US. The median age is 42.9 years, which is 10.3% 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 Merrimack County is $97,004, ranking #200 out of 3,222 counties — 29.1% above the national median. The poverty rate is 7.6% and unemployment stands at 3.1%.
Median Household Income Trend
Rankings →Income Distribution
Industry of Employment
Occupation
Housing
The median home value in Merrimack County is $367,600 (+30.4% vs national). Renters pay a median of $1,360/mo and the homeownership rate is 73.5%.
Median Home Value Trend
Rankings →Household Type
Education
In Merrimack County, 38.9% of adults age 25+ hold a bachelor's degree or higher, which is 15.5% above the national average, ranking #315 out of 3,222 counties.
Bachelor's Degree or Higher Trend
Rankings →Health & Wellbeing
Life expectancy in Merrimack County is 79.0 years. 13.0% of adults report poor or fair health and 6.9% lack health insurance. Data from County Health Rankings (2025).
Life Expectancy Trend
Substance Use
12.1% of adults in Merrimack County smoke , 30.7% are obese , and 22.5% report excessive drinking. The drug overdose death rate is 29.3 per 100,000.
Adult Smoking Trend
Safety
The homicide rate in Merrimack County is 2.3 per 100,000 and the suicide rate is 21.2 per 100,000. Motor vehicle deaths occur at a rate of 9.4 per 100,000.
Homicide Rate Trend
Families & Children
8.0% of children in Merrimack County live in poverty and the infant mortality rate is 3.5 per 1,000 live births. The teen birth rate is 5.2 per 1,000 females age 15–19.
Infant Mortality Trend
Civic & Transportation
Voter turnout in Merrimack County is 75.3%. The mean commute time is 29.1 min, which is 5.5% above the national average.
Voter Turnout Trend
Mean Commute Time Trend
Rankings →Elections
In the 2024 presidential election, Merrimack County voted Democratic with a margin of 5.2%. The vote was 52.1% Dem / 46.9% Rep. Compared to 2020, the margin shifted 4.6 toward Republicans .
Vote Share Over Time
About Merrimack County, New Hampshire
Merrimack County, New Hampshire has a total population of 155,967, making it the 446th most populous county in the United States. The median age in Merrimack County is 42.9 years, which is 10.3% above the national median of 38.9 years.
The median household income in Merrimack County is $97,004, which ranks #200 of 3,222 counties nationwide. This is 29.1% above the national median of $75,149. The poverty rate is 7.6%, lower than the national rate of 12.6%. The unemployment rate stands at 3.1%.
The median home value in Merrimack County is $367,600, 30.4% above the national median. Renters in Merrimack County pay a median gross rent of $1,360 per month. The homeownership rate is 73.5%, compared to the national rate of 64.4%.
In Merrimack County, 38.9% of residents aged 25 and older hold a bachelor's degree or higher, 15.5% above the national average of 33.7%. Health insurance coverage stands at 94.9% of the population. The average commute time for workers is 29.1 min.
Merrimack County is a diverse community. The largest racial or ethnic group is White (non-Hispanic) at 90.1% of the population, followed by Two or More Races (3.6%) and Hispanic or Latino (2.7%).
All data for Merrimack County, New Hampshire 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.