Delmar, DE has a population of 1,792 and is the 11,674th largest city in the United States. The population density is 1,002 per sq mi which is 99% higher than the Delaware average and 1006% higher than the national average. The median age in Delmar is 33 which is approximately 18% lower than the Delaware average of 40. In Delmar, 47% of the population over 15 years of age are married, 95% speak English and 2% speak Spanish. 37% of Delmar residents were born in Delaware, 60% were born out of state, 0% were born outside of the United States and 3% were foreign born.