Alvan, IL has a population of 308 and is the 22,357th largest city in the United States. The population density is 388 per sq mi which is 75% higher than the Illinois average and 329% higher than the national average. The median age in Alvan is 37 which is approximately 2% lower than the Illinois average of 37. In Alvan, 59% of the population over 15 years of age are married, 98% speak English and 0% speak Spanish. 82% of Alvan residents were born in Illinois, 16% were born out of state, 1% were born outside of the United States and 2% were foreign born.