This paper presents the formulation and calibration of CATKE, a one-equation parameterization designed for modeling microscale ocean mixing. CATKE aims to improve the accuracy of ocean models by better representing the small-scale mixing processes that are crucial for large-scale ocean dynamics. The paper details the development of the model, its theoretical foundations, and the calibration process. CATKE is evaluated against observational data and applied in global climate models to demonstrate its effectiveness in capturing microscale mixing phenomena.