St. Charles, MI has a population of 1,992 and is the 11,044th largest city in the United States. The population density is 953 per sq mi which is 436% higher than the Michigan average and 952% higher than the national average. The median age in St. Charles is 46 which is approximately 15% higher than the Michigan average of 40. In St. Charles, 59% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 88% of St. Charles residents were born in Michigan, 10% were born out of state, 1% were born outside of the United States and 1% were foreign born.