Callahan, FL has a population of 1,203 and is the 14,013th largest city in the United States. The population density is 827 per sq mi which is 182% higher than the Florida average and 813% higher than the national average. The median age in Callahan is 36 which is approximately 14% lower than the Florida average of 42. In Callahan, 52% of the population over 15 years of age are married, 97% speak English and 2% speak Spanish. 65% of Callahan residents were born in Florida, 29% were born out of state, 2% were born outside of the United States and 3% were foreign born.