Hematology analyzers provide a static snapshot of the circulating population of red blood cells (RBCs). The RBC population is rapidly changing, with more than 2 million RBCs turning over every second in the typical healthy adult. The static snapshot provided by the complete blood count does not capture many of the dynamic aspects of this population, such as the rate of RBC maturation and the rate of RBC turnover. By integrating basic science with hematology analyzer measurements, it is possible to estimate the rates of these dynamic processes, yielding new insights into human physiology, with potential diagnostic application.