According to the US Census Bureau population estimates, there were 1,355,064 people living in New Hampshire in 2018. Hillsborough County was the most populated county with 414,917 residents, followed by Rockingham County with 308,377 residents, and Merrimack County with 150,981 residents. Coos County with a population of 31,490 was the least populated county in New Hampshire in 2018.

Use the map below to interactively explore the population of each county in New Hampshire in 2018. The data can also be explored further by sorting and filtering with the table below.