A resting heart rate chart gives the average heart rates that people should have when they aren't exerting energy through physical activity or movement, according to the American Heart Association. The average heart rate for adults who are 18 years old or older is 60 to 100 beats per minute.
A person must lie down or sit down and remain calm while having his heart rate checked, according to the American Heart Association. A resting heart rate is an important marker for heart function, which can change as a person ages. Illness, exercise, medication use and the air temperature are all factors that can affect a person's heart rate.