Piper City, IL has a population of 894 and is the 15,845th largest city in the United States. The population density is 1,633 per sq mi which is 635% higher than the Illinois average and 1703% higher than the national average. The median age in Piper City is 36 which is approximately 5% lower than the Illinois average of 37. In Piper City, 59% of the population over 15 years of age are married, 94% speak English and 6% speak Spanish. 84% of Piper City residents were born in Illinois, 15% were born out of state, 1% were born outside of the United States and 0% were foreign born.