Pediatric Weight Estimator

About this calculator

In emergencies where a child can’t be weighed, clinicians estimate weight from age using formulas like the APLS (Advanced Paediatric Life Support) rule: for children aged 1-5 years, weight (kg) is approximately (age in years x 2) + 8; other age-banded formulas cover infants and older children. These are quick approximations, not a substitute for an actual scale reading when one is available.

Estimated weight is critical in pediatric emergency medicine because so much of acute care — drug dosing, defibrillation energy, endotracheal tube size, fluid bolus volume — is calculated per kilogram of body weight, and a child in front of a crash cart usually can’t be weighed first. It’s the same logic behind the color-coded Broselow tape used in ambulances and ERs, which maps a child’s length to an estimated weight band.

This calculator takes a child’s age and returns an estimated weight in kilograms using the APLS formula, giving a fast reference figure for time-critical situations.