Data / Rankings / Population / Counties in New Hampshire

Counties in New Hampshire by population

Hillsborough County had the highest population of 10 counties in 2023, at 427,475. Coos County had the lowest, at 31,247. The median was 85,222 and the figure for New Hampshire was 1.4 million. Source: the U.S. Census Bureau.

Highest427,475Hillsborough County
Lowest31,247Coos County
Median85,22210 counties
New Hampshire1,401,530History

All counties, 2023

CSVChart (SVG)

Hillsborough CountyHillsborough County: 427,475 persons427,475Rockingham CountyRockingham County: 320,441 persons320,441Merrimack CountyMerrimack County: 156,883 persons156,883Strafford CountyStrafford County: 133,595 persons133,595Grafton CountyGrafton County: 92,764 persons92,764Cheshire CountyCheshire County: 77,680 persons77,680Belknap CountyBelknap County: 65,039 persons65,039Carroll CountyCarroll County: 52,398 persons52,398Sullivan CountySullivan County: 44,008 persons44,008Coos CountyCoos County: 31,247 persons31,247
persons. Source: U.S. Census Bureau. Retrieved 2026-10-08.

Full ranking

RankCounties2023
persons		Change on 2022
1Hillsborough County427,475+0.3%
2Rockingham County320,441+0.4%
3Merrimack County156,883+0.4%
4Strafford County133,595+0.9%
5Grafton County92,764-0.2%
6Cheshire County77,680+0.4%
7Belknap County65,039+0.6%
8Carroll County52,398+0.6%
9Sullivan County44,008+0.3%
10Coos County31,247-0.6%

Other periods

About this ranking

Resident population. Spain and the EU: 1 January, with Spanish figures from the official municipal register (Padrón). United States: Census Bureau population estimates for 1 July. Other countries and the World: World Bank mid-year estimates, which count all residents regardless of legal status or citizenship.

For Denmark, Statistics Denmark counts the registered resident population on 1 January. Greenland and the Faroe Islands are excluded. The annual series selects the first-quarter reference date from FOLK1A. The World Bank series exists for every country, so use it (through compare) to rank countries on one basis.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Annual estimates of the resident population for the United States, states and counties, 1 July (Population Estimates Program). https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-08.

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Rank Counties in New Hampshire by population using official data, and cite the source.
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Questions

Which county has the highest population?

Hillsborough County, with 427,475 in 2023, according to the U.S. Census Bureau.

Which county has the lowest population?

Coos County, with 31,247 in 2023.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Annual estimates of the resident population for the United States, states and counties, 1 July (Population Estimates Program). Retrieved 2026-10-08.

Population: other rankings

Counties in New Hampshire: more rankings