For adults, a healthy resting heart rate (RHR) is anywhere between 60 and 100 BPM. However, that figure changes as we grow older. For example, a normal RHR for an infant is anywhere from 100 to 190 BPM. In contrast, that number in an adult would indicate tachycardia, or an unusually rapid heart rate, which can lead to several critical medical issues. The healthy RHR range stays the same once you reach adulthood, whether you are 20, 40 or 80.