Carnegie Unit and Student Hour

The Carnegie Unit and the Student Hour are strictly time-based references for measuring educational attainment used by American universities and colleges; the Carnegie Unit assesses secondary school attainment, and the Student Hour, derived from the Carnegie Unit, assesses collegiate attainment. As per its original definition, the Carnegie Unit is 120 hours of class or contact time with an instructor over the course of a year at the secondary (American high school) level.

Source: Wikipedia — Carnegie Unit and Student Hour (CC BY-SA 4.0)