Normal Vital Signs by Age: Newborn to Adult Reference Chart

Quick answer: Normal resting vital signs change with age. Heart rate and respiratory rate are fastest at birth and slow toward adult values: newborns 100-160 bpm and 30-60 breaths/min, infants 90-160 and 30-50, toddlers 80-130 and 24-40, school-age children 70-110 and 18-30, adolescents and adults 60-100 and 12-20. Systolic BP rises from 60-90 mmHg in newborns to 90-120 in adults; temperature and SpO2 (95-100%) barely change.

Children are not small adults. A heart rate of 130 is significant tachycardia in a resting 50-year-old and completely normal in a 2-month-old. Vitals run fastest at birth and slow toward adult numbers as a child grows, so every range you memorize has to be anchored to age. The chart below gives the standard pediatric and adult reference ranges for heart rate, respiratory rate, blood pressure, temperature, and oxygen saturation, along with the red-flag values that should make you act.

Normal vital signs by age: the master chart

Use these awake, resting ranges. A sleeping infant will sit at the low end; a crying or febrile child will spike above the high end, which is expected and not automatically abnormal. The single most testable concept on the NCLEX is the trend: rates start high in the newborn and step down with each age band until they reach adult values.

Temperature and oxygen saturation do not shift much by age, so they get their own short table. A normal core temperature stays close to 37°C (98.6°F) across the lifespan, and a healthy child or adult breathing room air should hold an SpO2 of 95% or higher.

If you are studying the broader pediatric exam content, pair this chart with our pediatric nursing review, where these numbers show up inside full case scenarios.

Why do pediatric vital signs run faster and trend toward adult values?

It comes down to metabolism and body size. Newborns and infants have a high metabolic rate, high oxygen demand per kilogram, and a small stroke volume. Their hearts cannot pump much blood per beat, so they raise cardiac output by beating faster. The same logic drives respiratory rate: small lungs and a high oxygen demand mean more breaths per minute to keep up.

As a child grows, the heart and lungs enlarge, stroke volume and tidal volume increase, and the resting metabolic rate falls. The body no longer needs to run fast to meet its needs, so heart rate and respiratory rate drop steadily with each age band. By adolescence the numbers have settled into the adult range.

Blood pressure does the opposite. It is lowest in the newborn and climbs with age as the vascular system matures and the heart pumps against a larger circulation. For children aged 1-10 years, a handy rule for estimating the minimum acceptable systolic pressure is 70 + (2 × age in years). A 5-year-old’s lower limit is roughly 70 + 10 = 80 mmHg; fall below that and you should suspect hypotension. The thresholds differ at the edges of childhood: a neonate (0-28 days) is hypotensive below an SBP of 60, an infant (1-12 months) below 70, and a child older than 10 years below a flat 90 mmHg.

How do you count a pediatric heart rate and respiratory rate correctly?

Technique is tested, and getting it wrong is one of the easiest points to lose on the NCLEX.

Apical pulse, full minute, in infants and young children

In children under 2 years, count the apical pulse, not a radial or peripheral pulse. Place the stethoscope at the point of maximal impulse (the fourth intercostal space at the left midclavicular line in infants and young children; it drops to the fifth intercostal space at the midclavicular line by about age 7 and stays there through adulthood) and count for a full 60 seconds. Pediatric rhythms vary, and a short 15-second count multiplied out can miss an irregularity or simply give a wrong number. The radial pulse is unreliable in infants because their vessels are small and rates are fast.

Count respirations before you touch the child

Infants are obligate nose breathers and use their diaphragm, so they breathe abdominally. Watch the rise and fall of the abdomen and count for a full minute. Infant breathing is normally irregular, and brief pauses can occur, which is exactly why a partial count is unreliable. Count respirations before you take the pulse or otherwise disturb the child, because crying inflates the rate and ruins your reading.

Sequence matters

The least invasive measurements come first. Assess respiratory rate, then heart rate, while the child is calm or sleeping; save the blood pressure cuff and temperature for last. Use an age-appropriate BP cuff: a cuff that is too small reads falsely high, and a cuff that is too large reads falsely low. The bladder width should be about 40% of the arm circumference, and the bladder length should encircle 80-100% of the arm circumference, roughly a 2:1 length-to-width ratio.

What temperature counts as a fever, and when does it matter?

A fever is generally a temperature of 38.0°C (100.4°F) or higher. The route changes both the reading and the standard of care.

The age that changes management most is the very young. A rectal temperature of 38.0°C or higher in an infant under 28 days (and through about 3 months) is a medical emergency, not a wait-and-watch situation. Classically, these infants get a full sepsis workup — blood and urine cultures, lumbar puncture, and admission — because their immune systems are immature and they cannot localize infection. In current hospital practice the 2021 AAP guideline risk-stratifies well-appearing infants 8-60 days old, and only the youngest tier (8-21 days) automatically receives the lumbar puncture and admission; the older tiers may be sorted by inflammatory markers. For the exam, treat any febrile infant under 3 months as an escalation. Keep that one fact in your pocket: the febrile newborn always escalates.

Red flags and escalation: when vital signs demand action

Memorize the chart, then memorize the values that mean “do something now.” In children, the most dangerous sign is often the absence of a fast heart rate when you would expect one. A sick child compensates by speeding up; when a deteriorating child’s heart rate slows toward normal or below, that is frequently a sign of decompensation and impending arrest, not improvement.

• Bradycardia in a child: almost always due to hypoxia. The first response is to support oxygenation and ventilation, not to reach for atropine.
• Tachypnea plus retractions, nasal flaring, grunting, or head bobbing: these are signs of respiratory distress and increased work of breathing. Grunting in an infant is an ominous sign.
• SpO2 below 90% on room air: significant hypoxemia; below 92% in a child with respiratory illness warrants supplemental oxygen and reassessment.
• Hypotension in a child: a late sign of shock. Children hold their blood pressure until they crash, so do not wait for a low number to recognize shock. Watch heart rate, capillary refill (normal is under 2 seconds), and mental status instead.
• Febrile infant under 3 months (rectal 38.0°C / 100.4°F or higher): escalate for sepsis evaluation.
• Apnea in an infant: a pause longer than 20 seconds, or any pause with cyanosis or bradycardia, is pathologic and requires intervention.

The NCLEX priority framework still applies: airway, breathing, circulation. In a deteriorating child, breathing problems lead, because pediatric arrest is most often respiratory in origin.

Common NCLEX traps with pediatric vital signs

Here is how the test most often tries to catch you.

• Applying adult numbers to a child. A heart rate of 150 in a healthy sleeping infant is normal. The same number in an adult is marked tachycardia that demands investigation. Read the age first, every time.
• Treating a high rate as automatically wrong. A crying toddler with a heart rate of 140 and a respiratory rate of 38 is reacting to distress. Reassess when calm before you escalate.
• Mistaking compensated shock for stability. A child with a normal blood pressure, fast heart rate, cool extremities, and delayed capillary refill is in shock. That normal BP is exactly what the question wants you to trust.
• Ignoring route on temperature. An axillary temp of 37.5°C may correspond to a true core fever. Know which route was used.
• Choosing the radial pulse in an infant. The correct answer is the apical pulse for a full minute in children under two.
• Forgetting that bradycardia in kids means hypoxia. The intervention is oxygen and ventilation first, not cardiac drugs.

Frequently Asked Questions

Why do you count a pediatric pulse and respirations for a full minute?

Infant and young-child rhythms are normally irregular, and breathing can be periodic with brief pauses. A 15- or 30-second count multiplied out can miss an irregularity or produce a misleading number. A full 60-second count gives an accurate rate and lets you detect rhythm abnormalities.

At what age do a child’s vital signs match adult values?

By adolescence (roughly 12-18 years). Heart rate settles to about 60-100, respiratory rate to 12-20, and systolic blood pressure into the 90s to low 120s, which are essentially the adult ranges. Younger children run faster heart and respiratory rates and lower blood pressures.

What temperature is considered a fever in a child?

A temperature of 38.0°C (100.4°F) or higher, most reliably measured rectally in infants. In an infant under three months, a rectal temperature at or above this threshold is a reason to escalate for a sepsis evaluation rather than to observe at home.

Why is bradycardia so concerning in children?

Children normally compensate for illness by speeding up. A slowing heart rate in a sick or hypoxic child usually means the child is decompensating and approaching arrest. Because pediatric arrest is most often respiratory in origin, the first intervention for bradycardia is oxygenation and ventilation, not cardiac medication.

Why is low blood pressure a late sign of shock in children?

Children maintain their blood pressure through strong compensatory mechanisms, raising heart rate and constricting peripheral vessels, long after an adult would drop. By the time a child’s blood pressure falls, the compensation has failed and the child is critically ill. Recognize shock earlier by watching heart rate, capillary refill, skin temperature, and mental status.

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