Pediatric BP Percentile Calculator

AAP 2017 Clinical Practice Guidelines

📋 How to Use This Calculator

For Best Accuracy:

  1. Age: Enter the child's exact age using Years + Months (e.g., 8 years, 4 months). This matches how percentiles are calculated in the AAP reference tables.
  2. Height: Measure height accurately — small errors affect percentile calculations. The calculator will show a height z-score to help identify measurement errors.
  3. BP Measurement: Use the average of 2-3 auscultatory readings taken after 5 minutes of rest, per AAP guidelines.

Understanding Results:

  • Accuracy: Results are within ±1 percentile of published AAP tables
  • For ages ≥13: Classification uses absolute thresholds (120/130/140 mmHg) per adult guidelines
  • For ages <13: Classification uses both percentiles AND absolute thresholds, whichever is lower

When to Be Cautious:

  • ⚠️ Height z-score > 3 or < -3 may indicate measurement error
  • ⚠️ Ages <5 or >17 years are outside the validated range
  • ⚠️ Single readings should not be used to diagnose hypertension
💡 Tip: Use Years + Months for best accuracy with AAP tables
Systolic BP
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Diastolic BP
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BP Thresholds for this patient:

90th percentile:
95th percentile:
95th + 12 mmHg:
For educational purposes only. Not a substitute for professional medical judgment.
Accuracy: ±1 percentile ▸
Validation performed against:
  • AAP 2017 Table 4 — 24 test points, all within ±1 mmHg
  • Rosner sample data — 87.5% exact match, 100% within ±1 percentile
  • bsolomon.us calculator — BP values match to <0.01 mmHg
Sources of ±1 variation: floating-point rounding, integer percentile discretization
Flynn JT et al. Pediatrics 2017;140(3):e20171904 • Rosner B et al. Am J Epidemiol 2008;167(6):653-66