The measurement of age, age structuring, and the life course has become more problematic as the study of human lives has moved toward more detailed analyses and explanations. As we seek to better understand the course of human lives in contemporary and changing societies, the effective empirical measurement of its key concepts simultaneously becomes more pressing and more complicated. We first review the critical concepts of, and measurement strategies associated with, age and age structuring—including a discussion of different types of age, subjective age identification, age norms and age expectations, critical life events, life phases, and life review. We then discuss state-of-the-art methods for measuring the life course, especially through life history and event matrices, and we close the chapter with some comments on the organization, analysis, and modeling of data.