Average heart rates based on age can be found on WebMD. The average heart rate changes depending on whether a person is at rest or doing physical activity, states the American Heart Association.
The resting heart rate is equivalent to how many times the heart beats per minute while the body is at rest. For babies up to age one, the resting heart rate is 100-160 beats per minute; for children age one to 10 years, it is 70-120 beats per minute; for children age 11-17 and adults, it is 60-100 beats per minute. For well-conditioned athletes, that number goes down considerably to about 40 - 60 beats per minute, maintains WebMD.
A person’s maximum heart rate is equal to 220 minus his age. This is the highest level anyone's heart rate should reach when doing strenuous exercise. In order to get the most benefit from exercise, physical activity should be performed within the target heart-rate range; this is approximately 50 to 85 percent of the maximum heart rate. This is equal to between 100 and 170 beats per minute for a 20-year-old person; 90 to 153 beats per minute for a 40-year-old person; 80 to 136 beats per minute for a 60-year-old; and 75 to 128 beats per minute for someone who is 70 years old, claims the American Heart Association.