Colfax, IN has a population of 781 and is the 16,768th largest city in the United States. The population density is 2,149 per sq mi which is 1097% higher than the Indiana average and 2272% higher than the national average. The median age in Colfax is 39 which is approximately 3% higher than the Indiana average of 37. In Colfax, 64% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 84% of Colfax residents were born in Indiana, 15% were born out of state, 0% were born outside of the United States and 0% were foreign born.