Pediatric Assessment Triangle Calculator
Assess pediatric patients using the PAT appearance, work of breathing, and circulation. Enter values for instant results with step-by-step formulas.
Calculator
Adjust values & calculateTone, Interactiveness, Consolability, Look/Gaze, Speech/Cry
Retractions, nasal flaring, abnormal sounds, head bobbing
Color: pallor, mottling, cyanosis
Recommended Action
Standard assessment. Patient appears stable with normal appearance, breathing, and circulation. Proceed with routine evaluation and history taking.
Formula
The Pediatric Assessment Triangle combines three observational components assessed within 30 seconds. Each side is rated as normal or abnormal, and the combination of findings produces a clinical impression that guides urgency of intervention.
Last reviewed: January 2026
Worked Examples
Example 1: Toddler with Respiratory Distress
Example 2: Infant with Altered Mental Status and Mottled Skin
Background & Theory
The Pediatric Assessment Triangle Calculator applies the following established principles and formulas. Health and medicine calculators are grounded in validated physiological measurement methods established through decades of clinical research. Body Mass Index, or BMI, is calculated by dividing weight in kilograms by height in meters squared (kg/m²), a formula originating from Adolphe Quetelet's 19th-century statistical work and later codified by the WHO into standard classifications: underweight below 18.5, normal weight 18.5 to 24.9, overweight 25 to 29.9, and obese at 30 and above. Basal Metabolic Rate quantifies the minimum energy required to sustain life at rest. The Mifflin-St Jeor equation, published in 1990 and widely regarded as the most accurate for most adults, calculates BMR as (10 × weight in kg) + (6.25 × height in cm) − (5 × age) ± sex adjustment. The older Harris-Benedict equations, revised in 1984 by Roza and Shizgal, remain in common use. Total Daily Energy Expenditure is derived by multiplying BMR by a physical activity factor ranging from 1.2 for sedentary individuals to 1.9 for extremely active ones, following the methodology validated by doubly labeled water studies. Body fat percentage can be estimated without laboratory equipment using the U.S. Navy circumference method, which uses neck, waist, and hip measurements, or via BMI-derived equations adjusted for age and sex. The Jackson-Pollock skinfold method offers higher precision with calipers. Blood pressure classification, according to the American College of Cardiology and the 2017 ACC/AHA guidelines, defines normal as below 120/80 mmHg, elevated as 120 to 129 systolic, and hypertension stage 1 as 130 to 139 systolic or 80 to 89 diastolic. Target heart rate zones for aerobic exercise are derived from maximum heart rate estimates, most commonly using the formula 220 minus age in years, with moderate-intensity training typically defined as 50 to 70 percent of maximum heart rate and vigorous intensity at 70 to 85 percent, consistent with CDC and American Heart Association guidelines. These thresholds guide safe and effective cardiovascular conditioning.
History
The history behind the Pediatric Assessment Triangle Calculator traces back through the following developments. The history of health measurement stretches back to ancient Greece, where Hippocrates around 400 BCE laid the foundation for observational medicine by systematically recording patient symptoms, diet, and environment. His humoral theory, though scientifically superseded, established the principle that the body operates as an interconnected system subject to measurable imbalance. The transformation toward modern medicine accelerated in the 19th century. Louis Pasteur and Robert Koch developed germ theory in the 1860s and 1870s, identifying microorganisms as disease agents and enabling targeted interventions. Florence Nightingale, working during the Crimean War in the 1850s, introduced statistical analysis to nursing practice, demonstrating through data visualization that sanitation reduced mortality. Her work is foundational to evidence-based health measurement. The discovery of vitamins in the early 20th century, beginning with Casimir Funk's coinage of the term in 1912 and culminating in the isolation of vitamins A through K, created the field of nutritional science and gave rise to dietary reference intake frameworks. The World Health Organization, founded in 1948, subsequently established global standards for health metrics, disease classification through the International Classification of Diseases, and recommended daily allowances. The BMI as a clinical screening tool gained traction in the 1970s through Ancel Keys' large-scale epidemiological work, which validated Quetelet's index as a population-level obesity indicator. Through the 1980s and 1990s, the Framingham Heart Study produced landmark data linking cholesterol, blood pressure, and lifestyle factors to cardiovascular disease risk, directly shaping the numeric thresholds still used in health calculators. The evidence-based medicine movement, formalized by Gordon Guyatt and colleagues at McMaster University in the early 1990s, demanded that all health recommendations derive from systematically graded clinical evidence. The digital health era beginning in the 2000s brought these formulas to consumer devices, wearable sensors, and smartphone applications, expanding access to health self-monitoring on a global scale and enabling population-level data collection that continues to refine clinical reference ranges.
Frequently Asked Questions
Formula
PAT = Appearance + Work of Breathing + Circulation to Skin
The Pediatric Assessment Triangle combines three observational components assessed within 30 seconds. Each side is rated as normal or abnormal, and the combination of findings produces a clinical impression that guides urgency of intervention.
Worked Examples
Example 1: Toddler with Respiratory Distress
Problem: A 2-year-old presents with wheezing and intercostal retractions but is alert, interactive, and has pink skin. Assess using PAT.
Solution: Appearance: Normal (alert, interactive, consolable, good tone)\nWork of Breathing: Abnormal (wheezing, intercostal retractions)\nCirculation: Normal (pink, well-perfused skin)\nPAT Impression: Respiratory Distress\nThe child is compensating with increased work of breathing but maintaining adequate oxygenation.
Result: PAT: Respiratory Distress | Severity: Urgent | Child is compensating
Example 2: Infant with Altered Mental Status and Mottled Skin
Problem: A 6-month-old is lethargic, has weak cry, no respiratory distress, but mottled skin and pale extremities. Assess using PAT.
Solution: Appearance: Abnormal (lethargic, weak cry, poor tone)\nWork of Breathing: Normal (no distress signs)\nCirculation: Abnormal (mottled skin, pallor)\nPAT Impression: Decompensated Shock\nImmediate IV/IO access needed, fluid resuscitation with 20 mL/kg isotonic crystalloid.
Result: PAT: Decompensated Shock | Severity: Emergent | Immediate intervention needed
Frequently Asked Questions
What is the Pediatric Assessment Triangle?
The Pediatric Assessment Triangle, commonly known as the PAT, is a rapid observational tool used by emergency medical providers to quickly assess the severity of a pediatric patient within the first 30 seconds of an encounter without touching the child. It evaluates three components: appearance, which reflects the adequacy of ventilation, oxygenation, brain perfusion, and central nervous system function; work of breathing, which reflects the effort required to breathe; and circulation to the skin, which reflects the adequacy of cardiac output and perfusion. The PAT was developed by the American Academy of Pediatrics and is a cornerstone of the Pediatric Education for Prehospital Professionals program.
How does the PAT differ from other pediatric scoring systems?
Unlike numerical scoring systems such as the Glasgow Coma Scale or Pediatric Early Warning Score, the PAT is a purely observational tool that does not require vital signs, equipment, or physical contact with the patient for completion. This makes it uniquely suited for rapid initial assessment and triage situations where speed is essential and the child may be uncooperative or frightened. Other scoring systems like the PEWS require measured vital signs and may take several minutes to complete accurately with proper equipment. The PAT provides an immediate general impression that guides the urgency and direction of further assessment, while detailed scoring systems provide more precise monitoring data over time. Both types of tools are complementary and should be used together for comprehensive patient evaluation.
How do pediatric calculations differ from adult calculations?
Pediatric dosing is weight-based (mg/kg) or BSA-based (mg/m^2) because children are not small adults — they have different pharmacokinetics. Use actual body weight, check age-appropriate ranges, and never exceed adult maximum doses. The Young formula (age/(age+12) * adult dose) and Clark formula (weight/150 * adult dose) provide rough estimates only.
Is my data stored or sent to a server?
No. All calculations run entirely in your browser using JavaScript. No data you enter is ever transmitted to any server or stored anywhere. Your inputs remain completely private.
Can I use Pediatric Assessment Triangle Calculator on a mobile device?
Yes. All calculators on NovaCalculator are fully responsive and work on smartphones, tablets, and desktops. The layout adapts automatically to your screen size.
What inputs do I need to use Pediatric Assessment Triangle Calculator accurately?
Each field is labelled with the required unit (metric or imperial). Gather your source values before starting — for example, a weight measurement in kilograms, a distance in metres, or a dollar amount — and enter them exactly as measured. The formula section on this page lists every variable and explains what each represents.
References
Reviewed by Rahul Singh, Health & Wellness Specialist · Editorial policy