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Measurement and interpretation guide

Before entering a reading

  1. Seat the child quietly for 3–5 minutes with back supported, feet uncrossed, and the right arm supported at heart level.
  2. Use the correct cuff size. If the initial BP is elevated, obtain 2 additional readings at the same visit and average them; the Average 2–3 mode below performs the arithmetic.
  3. Confirm an elevated oscillometric average with 2 auscultatory readings and use their average for categorization.

What this result means

  • The output is the category for this reading, not a diagnosis.
  • For ages 1–12, the lower of the percentile-based or absolute AAP threshold applies. At age 13 and older, fixed AAP adolescent thresholds apply.
  • The BP model uses measured height directly. The CDC length/height percentile is shown as a measurement check and does not limit the BP model’s age range.

Patient and blood pressure inputs

Age entry
Fast path for the age shown in the EHR banner.
Required; retained when starting a new patient.
Sex used by the reference model
Length / height unit
Blood pressure readings

Blood pressure result

Systolic percentile
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Diastolic percentile
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Category for this reading

A single reading does not diagnose hypertension. Diagnosis requires auscultatory-confirmed high readings across separate visits.

AAP category thresholds for this reading

Distance to thresholds

Percentile reference values

90th percentile
95th percentile
95th percentile + 12 mmHg

Interactive BP reference curves

Switch between the actual category cutoffs and the underlying percentile curves. Hover, touch, or use the arrow keys on a chart to inspect values.

Systolic BP by age

Diastolic BP by age

AAP simplified screening table

These are screening cutoffs for deciding whether a reading needs further evaluation. They are intentionally conservative and are not diagnostic thresholds.

AgeMaleFemale
SBPDBPSBPDBP
198529854
21005510158
31015810260
41026010362
51036310464
61056610567
71066810668
81076910769
91077010871
101087210972
111107411174
121137511475
≥131208012080
Methods, references, and validation

Scope

This tool interprets office BP for ages 1–17. It is not an ABPM calculator, a hypotension reference, or a neonatal/infant-under-1 reference. It does not account for symptoms, comorbidities, cuff error, or treatment history.

Primary references

Validation

  • 1,904 published-table comparisons: both sexes, ages 1–17, seven height percentiles, SBP/DBP, and four printed rows (50th, 90th, 95th, 95th + 12).
  • Boundary coverage: pediatric/adolescent transition, all category edges, unit conversion, extreme percentiles, invalid inputs, and date handling.
  • Browser regressions: interaction, keyboard behavior, copy/print controls, graph rendering, mobile overflow, internal links, and runtime errors.
Read the validation report and acceptance criteria

Displayed BP z-scores are normal-equivalent z values derived from interpolation across the Rosner 1st–99th quantile curves; values outside that modeled range are reported as bounded rather than extrapolated.

Version 3.1 • Implementation and automated test suite reviewed August 3, 2026; this is not independent clinical certification. Calculations run locally in your browser. Patient entries are neither submitted nor stored; only the height-unit preference is retained on this device.

Clinical support, not medical advice. Verify unexpected values and use current institutional guidance and clinical judgment. A result from one reading must not be presented as a hypertension diagnosis.

Built from AAP 2017 / Rosner reference methods • No external scripts, trackers, or patient-data submission