Dover, NH has a population of 30,750 and is the 1,382nd largest city in the United States. The population density is 1,150 per sq mi which is 714% higher than the New Hampshire average and 1170% higher than the national average. The median age in Dover is 36 which is approximately 14% lower than the New Hampshire average of 42. In Dover, 52% of the population over 15 years of age are married, 92% speak English and 1% speak Spanish. 43% of Dover residents were born in New Hampshire, 48% were born out of state, 1% were born outside of the United States and 8% were foreign born.