Calculate the heart rate by first finding the pulse at either the wrist or the neck. Then, count the number of beats in a 15-second period, and multiply that number by four to establish the overall heart rate, says Edward R. Laskowski, M.D.
The heart rate changes frequently depending on the individual’s activity. As a person sleeps, cleans or works out, the heart rate varies, according to WebMD. When someone is resting, the heart rate is much slower than when doing physical activities. The pulse is checked to determine how fit a person is, how well the heart is working, blood flow and vessel blockage.