Capitol Heights, MD has a population of 4,489 and is the 6,932nd largest city in the United States. The population density is 5,749 per sq mi which is 1112% higher than the Maryland average and 6246% higher than the national average. The median age in Capitol Heights is 36 which is approximately 5% lower than the Maryland average of 38. In Capitol Heights, 34% of the population over 15 years of age are married, 94% speak English and 3% speak Spanish. 26% of Capitol Heights residents were born in Maryland, 66% were born out of state, 1% were born outside of the United States and 7% were foreign born.