Normal Vital Sign Ranges for Adults and Children
For adults, normal blood pressure is <120/<80 mm Hg, normal resting heart rate is approximately 72 beats/min, and normal respiratory rate is approximately 12-20 breaths/min; for children, blood pressure is defined by age/sex/height percentiles with normal BP <90th percentile, heart rate decreases from ~129 beats/min in infancy to ~72 beats/min in adolescence, and respiratory rate decreases from ~44 breaths/min at birth to ~26 breaths/min by age 2 years. 1, 2, 3, 4
Blood Pressure Guidelines
Adults
The 2025 AHA/ACC guideline provides the current standard for adult blood pressure classification 1:
- Normal BP: <120/<80 mm Hg
- Elevated BP: 120-129/<80 mm Hg
- Stage 1 Hypertension: 130-139/80-89 mm Hg
- Stage 2 Hypertension: ≥140/≥90 mm Hg
These thresholds are based on average readings from ≥2 careful measurements obtained on ≥2 separate occasions. When systolic and diastolic values fall into different categories, classify by the higher category. 1
Children and Adolescents
The 2017 AAP guideline establishes age-specific definitions 2:
For children aged 1-13 years:
- Normal BP: <90th percentile (based on age, sex, and height)
- Elevated BP: ≥90th percentile to <95th percentile, or 120/80 mm Hg to <95th percentile (whichever is lower)
- Stage 1 HTN: ≥95th percentile to <95th percentile + 12 mm Hg, or 130/80-139/89 mm Hg (whichever is lower)
- Stage 2 HTN: ≥95th percentile + 12 mm Hg, or ≥140/90 mm Hg (whichever is lower)
For adolescents ≥13 years:
- Normal BP: <120/<80 mm Hg
- Elevated BP: 120/<80 to 129/<80 mm Hg
- Stage 1 HTN: 130/80 to 139/89 mm Hg
- Stage 2 HTN: ≥140/90 mm Hg
Critical caveat: The pediatric BP tables are now based on normal-weight children only (BMI <85th percentile), making values several mm Hg lower than older references that included overweight/obese children. This change reflects the strong association between elevated BMI and higher BP. 2
Heart Rate (Pulse) Ranges
Adults
National reference data from 1999-2008 establishes that adult resting pulse rate plateaus at approximately 72 beats/min (SE 0.2) 3:
- Males ≥20 years: 71 beats/min (SE 0.3)
- Females ≥20 years: 74 beats/min (SE 0.2)
Clinical thresholds:
- Tachycardia: ≥100 beats/min (prevalence: 1.3% in males, 1.9% in females)
- Bradycardia: <60 beats/min (prevalence: 15.2% in males, 6.9% in females)
Males have 2.43 times higher odds of bradycardia but 0.71 times lower odds of tachycardia compared to women. 3
Children
Heart rate shows dramatic age-related decline 3, 4:
- <1 year: Mean 129 beats/min (SE 0.9)
- Age 5 years: Mean 96 beats/min (SE 0.5)
- Early adolescence: Mean 78 beats/min (SE 0.3)
- Peak at 1 month: 145 beats/min before declining
A systematic review of 143,346 children confirms heart rate peaks at approximately 1 month of age (145 beats/min), then decreases to 113 beats/min by age 2 years. 4
Gender differences: Females have significantly higher resting pulse rates than males in two age groups: infants <1 year (90 vs 86 beats/min) and adults ≥20 years (74 vs 71 beats/min). 3
Respiratory Rate Ranges
Adults
While specific adult respiratory rate guidelines are not provided in the evidence, standard clinical practice recognizes 12-20 breaths/min as normal for adults at rest.
Children
Respiratory rate shows steep decline in early childhood 4:
- Birth: Median 44 breaths/min
- Age 2 years: Median 26 breaths/min
- Early adolescence: Continues gradual decline
The steepest fall occurs in infants under 2 years of age. A systematic review of 3,881 children provides evidence-based centile charts showing this decline from birth to 18 years. 4
Important note: Current widely-used reference ranges (such as APLS guidelines) show poor alignment with evidence-based centiles, particularly for respiratory rate, with published ranges frequently exceeding the 99th and 1st centiles or crossing the median. 4, 5
Key Clinical Considerations
Measurement technique matters: All vital signs should be obtained after the patient has been seated and rested quietly for approximately 4 minutes to ensure accurate resting values. 3
Body size does NOT correlate: Recent evidence in toddlers shows no correlation between height/weight and heart rate or respiratory rate, challenging previous assumptions. 6
Environmental factors: Longer outdoor playtime is associated with lower heart rate in children (111.7 beats/min in those with almost no outdoor play vs 108.2 beats/min in those with ≥3 hours/day). 6
Racial/ethnic differences exist: Non-Hispanic Black males have significantly lower mean resting pulse rate (74 beats/min) compared to non-Hispanic White males (77 beats/min) after controlling for age. 3