New Hampshire Population By County in 2021

Updated on June 16, 2025.

Based on the US Census Vintage data estimates, in 2021, the population of New Hampshire was 1,387,677. Among all New Hampshire counties, Hillsborough had the highest population (424,475), followed by Rockingham (318,349), and Merrimack (154,627).

Hover over or click on the counties in the map below to see the populations. The data can also be found in a table below. You can use the table to sort, filter, and explore the data further.

You can see similar information for other states and by state for the United States.

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New Hampshire Population By County in 2021
New Hampshire Population By County in 2021
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County Population % of State Population
Belknap 64598 4.66
Carroll 51735 3.73
Cheshire 76849 5.54
Coos 31387 2.26
Grafton 90508 6.52
Hillsborough 424475 30.59
Merrimack 154627 11.14
Rockingham 318349 22.94
Strafford 131540 9.48
Sullivan 43609 3.14