How old are you? Do you know your real age? Real age is the difference between your chronological and biological age. It is a scientific evaluation of how fast your body is aging, a rate that can be significantly younger than your calendar age, explains Dr. Michael Roizen, chair of anesthesiology and critical care at University of Chicago hospitals.In the last fifteen years alone, science has allowed us to make significant choices that affect how quickly we age. Studies now show that making such healthy choices can actually reverse the rate of aging that you have accumulated.