Chambersburg, PA has a population of 20,576 and is the 2,107th largest city in the United States. The population density is 2,971 per sq mi which is 972% higher than the Pennsylvania average and 3180% higher than the national average. The median age in Chambersburg is 36 which is approximately 12% lower than the Pennsylvania average of 41. In Chambersburg, 50% of the population over 15 years of age are married, 84% speak English and 13% speak Spanish. 63% of Chambersburg residents were born in Pennsylvania, 26% were born out of state, 3% were born outside of the United States and 8% were foreign born.