Calera, AL has a population of 12,839 and is the 3,240th largest city in the United States. The population density is 533 per sq mi which is 479% higher than the Alabama average and 488% higher than the national average. The median age in Calera is 33 which is approximately 14% lower than the Alabama average of 39. In Calera, 64% of the population over 15 years of age are married, 94% speak English and 4% speak Spanish. 69% of Calera residents were born in Alabama, 27% were born out of state, 1% were born outside of the United States and 3% were foreign born.