As of the 2010 census Kountze had a population of 2,123.
In the city, the population was spread out with 29.1% under the age of 18, 8.9% from 18 to 24, 28.6% from 25 to 44, 20.7% from 45 to 64, and 12.7% who were 65 years of age or older.