PECARN Calculator

Written by Great Medico

Updated September 24, 2026 •2 min read

Share Print Save

Small differences in pediatric inputs can change the answer quickly. PECARN Calculator keeps the calculation focused on the age, weight, measurements, or clinical branch actually implemented in the plugin.

What this calculator does

PECARN Calculator uses Age, A. ≥1 high-risk signs present, and B. ≥1 age-specific PECARN intermediate-risk signs present to calculate PECARN ciTBI risk branch. Where supported, it also shows Age branch, A criteria, and B criteria so the primary result is easier to check. It follows the exact field flow and engine behavior in this plugin rather than describing a different calculator with the same name. Children are not simply small adults: age, weight, gestational history, formulation, and clinical setting can change how a result should be used. Pediatric outputs deserve extra attention to units and the population for which the method was developed.

How to use it

Enter or select Age, A. ≥1 high-risk signs present, and B. ≥1 age-specific PECARN intermediate-risk signs present. Use the units offered by the calculator and keep paired laboratory or treatment values from the same clinical episode whenever the formula assumes that. If an entry is unknown, do not substitute a guess simply to obtain a number.

How the calculation works

The calculator selects the PECARN age branch (<2 years or ≥2 years), then uses whether any high-risk or age-specific intermediate-risk signs are present. It returns the stored ciTBI risk estimate and the corresponding higher-risk, observation-versus-CT, or very-low-risk branch.

Example

Using the sample values prefilled in this calculator, the primary result is <0.05 % ciTBI (Very-low-risk PECARN branch — CT generally not indicated), Age branch is ≥2 years, and A criteria is None. This example demonstrates the plugin’s own calculation path; replace the sample inputs with verified values before interpreting a real result.

How to interpret the result

The result describes the PECARN branch and approximate ciTBI risk under the rule’s intended conditions. It informs CT-versus-observation decisions; it is not a diagnosis of brain injury.

Limitations and notes

PECARN applies to appropriate minor blunt head-trauma presentations and depends on correct clinical assessment. It does not replace emergency evaluation, and infants under 3 months, worsening symptoms, bleeding disorders, nonaccidental trauma concerns, or presentations outside the derivation context need particular caution.