New Hampshire Counties by Population (2026)
2026 Pop.
50K
100K
150K
200K
250K
300K
350K
400K
Top 5 Most Populous Counties
435,948
325,969
159,489
135,390
93,317
| County | 2026 Pop. ↓ | Area (mi²) | Density (/mi²) | Change (2020) |
|---|---|---|---|---|
| Hillsborough County | 435,948 | 877 | 497 | 3.08% |
| Rockingham County | 325,969 | 695 | 469 | 3.59% |
| Merrimack County | 159,489 | 933 | 171 | 3.54% |
| Strafford County | 135,390 | 367 | 369 | 3.29% |
| Grafton County | 93,317 | 1.7K | 55 | 2.32% |
| Cheshire County | 78,970 | 707 | 112 | 3.17% |
| Belknap County | 65,733 | 402 | 164 | 3.07% |
| Carroll County | 52,994 | 932 | 57 | 5.48% |
| Sullivan County | 44,024 | 538 | 82 | 2.22% |
| Coos County | 30,864 | 1.8K | 17 | -1.17% |
Sources
- US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
- US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
- American Community Survey (2009 - 2013)
- Census QuickFacts
- Historical Populations of States and Counties (1790 - 1990)