Merrimack County Flag

Merrimack County

State:
New Hampshire
County Seat:

Merrimack County's estimated 2025 population is 158,679 with a growth rate of 0.51% in the past year according to the most recent United States census data. Merrimack County is the 3rd largest county in New Hampshire. The 2010 population was 146,395 and has seen a growth of 8.39% since that time.

158,679
Total Population
170
Population Density (mi²)
3
Population Rank (State)
810 0.51%
Annual Population Growth

Merrimack County Population

Demographics

Economics and Income Statistics

Sources

  1. City and Town Population Totals: 2020-2024
  2. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  3. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  4. American Community Survey (2009 - 2013)
  5. Census QuickFacts
  6. Historical Populations of States and Counties (1790 - 1990)