County Maps US

Merrimack County, New Hampshire

A county in New Hampshire, ranked 3 of 10 by population.

CountyFIPS 33013

Within New Hampshire
Merrimack County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks Concord, the county seat, located via the 2025 Census Gazetteer.

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Population
158,078
+4,017 (+2.6%) since 2020
Land area
932.9
square miles. A further 2.3% of the total area is water
Population density
169
people per square mile, computed rather than published
County seat
Concord
Seat of county government.
Established
1823
202 years ago
Largest city
Concord city
Population 44,597.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Merrimack County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Merrimack County, New Hampshire from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 800 by 777 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Merrimack County ranks

Position among the 10 counties of New Hampshire, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn New HampshireNationally
Population158,0783rd of 10445th of 3,144
Land area932.9 sq mi3rd of 10768th of 3,144
Population density169 per sq mi4th of 10634th of 3,144
Median household income$97,0043rd of 10200th of 3,143

Full data for Merrimack County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population158,078Vintage 2025 Population Estimates
Population in 2020154,061Vintage 2025 Population Estimates
2020 estimates base?153,816Vintage 2025 Population Estimates
Land area932.9 sq mi2025 Gazetteer Files
Water area22.1 sq mi2025 Gazetteer Files
Total area955 sq mi2025 Gazetteer Files
Population density?169 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$97,004American Community Survey 2020-2024 5-Year Estimates
Median home value$367,600American Community Survey 2020-2024 5-Year Estimates
Median age42.9American Community Survey 2020-2024 5-Year Estimates
Households60,901American Community Survey 2020-2024 5-Year Estimates
Housing units66,497American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
-411
1,209 births, 1,620 deaths
Net migration
+940
More people moved in than moved out.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 6 areas bordering Merrimack County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
Hillsborough CountyNew Hampshire45 mi433,415
Belknap CountyNew Hampshire37 mi65,147
Sullivan CountyNew Hampshire29 mi43,961
Rockingham CountyNew Hampshire21 mi324,077
Grafton CountyNew Hampshire19 mi93,225
Strafford CountyNew Hampshire0.9 mi135,043

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

All 10 counties of New Hampshire

Open the interactive New Hampshire county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.