Resting heart rate is the number of times your heart beats per minute when you are at rest. It is an indicator of both fitness and general health, and can vary depending on age, gender, and other factors. Here are the expected resting heart rate ranges by age:

• Newborn babies: 100 to 205 beats per minute
• Infants under 1 year: 100 to 180 beats per minute
• 1 to 2 years old: 98 to 140 beats per minute
• 3 to 4 years old: 80 to 120 beats per minute
• 5 to 6 years old: 75 to 115 beats per minute
• 7 to 9 years old: 70 to 110 beats per minute
• 10 years and older: 60 to 100 beats per minute

It is important to note that these ranges are for children while they are awake, and they will likely be lower when they are asleep. For adults (ages 18+), the expected resting heart rate range is 60 - 100 bpm. However, an important detail to keep in mind is that if you are very physically active, you might have a resting heart rate under 60 beats per minute. Competitive athletes can have resting heart rates as low as 40 bpm or so.