Carpentersville, IL has a population of 38,275 and is the 1,085th largest city in the United States. The population density is 4,849 per sq mi which is 2081% higher than the Illinois average and 5252% higher than the national average. The median age in Carpentersville is 30 which is approximately 19% lower than the Illinois average of 37. In Carpentersville, 55% of the population over 15 years of age are married, 47% speak English and 45% speak Spanish. 57% of Carpentersville residents were born in Illinois, 10% were born out of state, 2% were born outside of the United States and 31% were foreign born.