Caldwell, KS has a population of 1,137 and is the 14,371st largest city in the United States. The population density is 1,064 per sq mi which is 2932% higher than the Kansas average and 1074% higher than the national average. The median age in Caldwell is 51 which is approximately 41% higher than the Kansas average of 36. In Caldwell, 61% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 66% of Caldwell residents were born in Kansas, 34% were born out of state, 0% were born outside of the United States and 0% were foreign born.