Estimate, Median Age by Sex, Total Population (5-year estimate) in Johnson County, IN was 37.90000 Years of Age in January of 2022, according to the United States Federal Reserve. Historically, Estimate, Median Age by Sex, Total Population (5-year estimate) in Johnson County, IN reached a record high of 37.90000 in January of 2022 and a record low of 36.40000 in January of 2010. Trading Economics provides the current actual value, an historical data chart and related indicators for Estimate, Median Age by Sex, Total Population (5-year estimate) in Johnson County, IN - last updated from the United States Federal Reserve on May of 2024.