Counties · New Hampshire

Counties of New Hampshire

New Hampshire has 10 counties. Hillsborough County is the largest with 433,415 residents in 2025. 10 of the 10 gained residents between 2020 and 2025 by the Census Bureau's estimates.

What counties are in New Hampshire?

Sorted by the 2025 population estimate; sort by any column.

Counties of New Hampshire: 2025 estimate, change since 2020, ACS 2020-2024 5-year estimates

Hillsborough County	433,415	+2.5%	47	103	$103,545	$421,100
Rockingham County	324,077	+3.1%	47	73	$118,331	$497,500
Merrimack County	158,078	+2.8%	39	39	$97,004	$367,600
Strafford County	135,043	+3.2%	17	30	$88,570	$362,800
Grafton County	93,225	+2.3%	53	28	$88,261	$344,500
Cheshire County	78,269	+2.4%	31	18	$83,329	$280,100
Belknap County	65,147	+2.3%	16	18	$92,783	$374,900
Carroll County	52,784	+5.3%	28	19	$86,463	$388,900
Sullivan County	43,961	+2.1%	18	11	$80,858	$268,700
Coos County	31,343	+0.2%	26	11	$57,677	$188,900

Source: PEP Vintage 2025 (CO-EST2025); American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Census population estimates

How these figures are made: methodology and release checks · reading a margin of error · every state · corrections