The normal heart rate range for adults, including those who are 25 years old, is 60 to 100 beats per minute, as noted by the American Heart Association. That is only an average range, so some people might have fewer or more beats per minute.
A person who is very athletic might have a heart rate that is at the lower end of that range or lower, states the American Heart Association. A person who is obese might have a heart rate at the high end of that range. Other factors, including air temperature, medication use and body position, can affect the heart rate. The heart rate should always be taken while a person is lying down or sitting.