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Dr. Alessandro Giardini
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Heart rate varies widely trough the different stages of childhood. A newborn whose pulse beats 145 times per minute is entirely well; a teenager with the same reading at rest would warrant a clinical assessment. Age-specific reference values are the only reliable guide.
The heart rate is largely controlled by nerves that either accelerate or slow down the heart rate when stimulated. This is called the autonomous nervous system. The autonomic nervous system is not fully mature at birth. Sympathetic activity, which accelerates the heart, dominates in the newborn period. Parasympathetic tone, which slows it, develops more gradually over the first years of life. This maturation explains why resting heart rates in infants are so much higher than those in school-age children or adolescents.
There is a small and clinically important peak at around one month of age. Median heart rate rises from approximately 127 beats per minute at birth to a maximum of around 145 beats per minute at four weeks, before beginning a steady, progressive decline. Fleming and colleagues captured this pattern in a landmark 2011 systematic review published in The Lancet, which analysed data from 143,346 children. That study remains the most rigorous evidence base for paediatric heart rate reference values and informs the table below.
By the age of two, the median heart rate has dropped to around 113 beats per minute. From there the decline continues, more gradually, until adult values are reached in mid to late adolescence.
The values below represent the normal resting, awake heart rate for children at each stage from birth to 18 years. They reflect the 2nd to 98th centile range (the normal range) derived from the best available evidence, including Fleming et al. (2011) and the Advanced Paediatric Life Support (APLS) clinical guidelines used across the United Kingdom.
All values apply to a child who is calm, awake, and resting. Sleeping rates are typically 5 to 10 beats per minute lower than the figures shown. Single readings taken during fever, distress, or physical activity should not be compared directly against these ranges.
Normal reference values apply to a child who is calm, awake, and has been resting for at least five minutes. Departures from those conditions produce real departures from those values, and understanding why is clinically important.
Fever is the most consistent physiological cause of a raised rate. Each degree Celsius above normal adds approximately 10 beats per minute to the resting heart rate. Parents often check a pulse during an illness and compare it against a reference chart, which understandably produces alarm. Context explains almost everything.
Emotion and distress are equally powerful influences that parents frequently underestimate. In my private clinics across London, I regularly see families who measured their child's pulse during crying, anxiety, or separation from a parent. Rates of 170 to 180 beats per minute in a frightened toddler are entirely normal. A reading taken immediately after a tantrum tells you nothing about cardiovascular health.
Sleep reduces the resting rate by approximately 5 to 10 beats per minute compared to waking values. Reference charts based on awake measurements will therefore read as slightly elevated for a sleeping child, and this is expected.
Sex differences emerge in later childhood and adolescence. Boys tend to develop slightly lower resting rates than girls from around age ten, reflecting differences in autonomic maturation. The magnitude is modest, typically five to eight beats per minute, but it is worth considering when interpreting readings in teenagers.
A resting rate above the upper limit for age, on more than one measurement taken in different circumstances, deserves clinical attention. Single isolated readings during illness or upset can be safely put in the context. Persistent resting tachycardia is a different matter entirely.
Supraventricular tachycardia, or SVT, is the arrhythmia I encounter most frequently in children and adolescents in my clinics across London. In SVT, an abnormal electrical pathway triggers a sudden, very fast rhythm. Rates can reach 200 to 280 beats per minute. Children typically describe an abrupt uncomfortable pounding in the chest that may resolve just as suddenly as it started, often after coughing, drinking cold water, or bearing down.
Persistent resting tachycardia combined with fatigue, breathlessness, or reduced exercise tolerance requires prompt evaluation. This pattern can be the earliest presentation of dilated cardiomyopathy, myocarditis, or significant anaemia. These conditions are uncommon, but a persistently elevated rate without obvious explanation is precisely the finding that should prompt specialist referral.
Bradycardia is considerably less common than tachycardia in the general paediatric population, but it carries more diagnostic weight when it does appear.
Athletic training is the most benign explanation for a lower-than-expected resting rate. Regular endurance exercise increases stroke volume (the amount of blood that the heart ejects with every beat), and the heart therefore needs fewer beats to deliver the same output at rest. A competitive teenage cyclist with a resting rate of 48 beats per minute often has a structurally excellent heart. A clinician should still exclude other causes rather than assuming fitness alone accounts for the finding.
The cases I take most seriously involve bradycardia combined with symptoms: dizziness, near-fainting, or exercise intolerance. These require a 12-lead ECG and often ambulatory monitoring. Congenital heart block and sick sinus syndrome are rare but important diagnoses in children, particularly those born with structural heart disease or those who have undergone cardiac surgery. Some medications, notably beta-blockers used to treat hypertrophic cardiomyopathy or long QT syndrome and certain arrhythmias, also lower the resting rate as part of their intended pharmacological effect, and a lower rate in those children may simply reflect appropriate treatment rather than a new problem.
The most reliable manual method takes 60 seconds. Place two fingers on the inside of the wrist just below the thumb, or on the side of the neck below the jaw. Count each beat for a full minute. The child should have been sitting quietly for at least five minutes beforehand, and the measurement should not follow any physical activity, strong emotion, or a recent meal.
Pulse oximeters, now common in many households, display heart rate alongside oxygen saturation and are reasonably accurate when the fingers are warm and the child is still. Most modern smartwatches with optical sensors give a comparable resting estimate. Neither replaces a clinical 12-lead ECG, which records the electrical activity of the heart directly and provides information no wrist-worn device can replicate.
If a reading consistently falls outside the normal range for your child's age, or if you notice a very fast, very slow, or irregular rhythm, write down the reading, the time, and what your child was doing beforehand. Bring that record to your next consultation. That information shapes the clinical picture significantly and helps avoid unnecessary repeat visits.
A normal resting heart rate for a newborn in the first month of life ranges from 100 to 160 beats per minute. The median is approximately 127 beats per minute at birth, rising to a peak of around 145 beats per minute at one month of age before gradually declining.
A resting heart rate of between 80 and 150 beats per minute is normal for a baby aged 6 to 12 months. The median is approximately 120 beats per minute. Rates are typically 5 to 10 beats per minute lower during sleep.
For a child aged 1 to 2 years, a resting heart rate between 80 and 140 beats per minute falls within the normal range. The median around this age is approximately 113 beats per minute, reflecting the significant decline from the high rates of early infancy.
A resting heart rate of 75 to 125 beats per minute is normal for a child aged 2 to 5 years. By age 5, most children have a median resting rate of around 103 beats per minute.
For a school-age child between 8 and 12 years, a resting heart rate of 60 to 105 beats per minute is within the normal range. The median is approximately 82 beats per minute at 10 years of age.
A normal resting heart rate for a teenager aged 12 to 18 years ranges from 50 to 100 beats per minute, progressively approaching adult values. Well-trained athletes may have resting rates as low as 45 beats per minute without this indicating any problem.
Tachycardia in children is a persistently elevated resting heart rate above the upper normal limit for age. For a newborn this threshold is approximately 160 beats per minute; for a 5-year-old, around 125 beats per minute; and for a teenager, 100 beats per minute. A single elevated reading during fever, distress, or physical activity does not constitute clinical tachycardia.
Bradycardia in children is a persistent resting heart rate below the lower limit for age. For an infant this means below approximately 80 to 100 beats per minute; for a school-age child, below 60 beats per minute. Physically active or athletic children may have lower resting rates without this representing pathology.
Yes. A child's heart rate during sleep is typically 5 to 10 beats per minute lower than their waking resting rate. This reflects the normal shift in autonomic balance during sleep and does not indicate a problem.
A paediatric cardiology assessment is appropriate if your child has a consistently fast or slow resting heart rate for their age, reports palpitations, dizziness, or fainting, or if a healthcare professional has raised a concern following an ECG or routine examination. Early assessment is always preferable to prolonged monitoring at home when uncertainty exists.
Author: Dr. Alessandro Giardini, MD, PhD
Written 13/05/2026