A tool to support the clinical decisions of doctors and health professionals, not for self-diagnosis or self-treatment.
This calculator is inside the patient's file in Clinicato: open it from "Medical tools" while you chart the visit, it fills in from the patient's details and vital signs where they are recorded, and adds its result to the visit's plan in one tap, with the "Medical tools" add-on. Try it in your clinic
Calculator
How it works and when to use it
BMI is worked out as for adults (weight ÷ height in metres squared), but it is not classed with the adult cut-offs, it is read on the BMI-for-age chart by sex.
WHO, 5 to 19 years: overweight above +1 SD and obesity above +2, under 5 years: overweight above +2 and obesity above +3, and the CDC charts from 2 to 19 years: overweight from the 85th percentile and obesity from the 95th.
Reference: BMI = weight (kg) / height (m)²; read on BMI-for-age charts: WHO Child Growth Standards (2006, under 5: overweight > +2 SD, obesity > +3 SD), WHO Growth Reference 5-19 years (2007: overweight > +1 SD, obesity > +2 SD, thinness < −2 SD), CDC 2000 growth charts (2-19 years: overweight 85th to < 95th percentile, obesity ≥ 95th)
Frequently asked questions
Why does it not give the percentile?
A percentile needs the official chart tables for each month of age, so the calculator gives the number and the cut-offs, and the doctor places it on the chart.
Is BMI enough to judge a child's weight?
No, the doctor follows the growth trend over visits, measures height and weight and asks about food and activity first.
Tools you may also need
- Pediatric dose calculator The dose in mg and mL, and the daily total within its maximums.
- Maintenance fluids calculator (Holliday-Segar) Maintenance fluids in mL a day and an hour.
- Corrected age calculator Chronological and corrected age, or postmenstrual age before the due date.
- Apgar score calculator The Apgar score of 10 and what it means at that minute.
- Pregnancy weight gain calculator The recommended total gain, its weekly rate, and the gain so far.
- Body surface area (BSA) calculator Body surface area in m² by two formulas.
Clinic software for this specialty
Try Clinicato for your clinic
These calculators are free here for everyone, and in Clinicato 49 medical tools work inside the patient's file with the "Medical tools" add-on: filled from the visit and the vital signs, with the result added to the visit's plan, next to appointments, prescriptions and invoices.