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Ideal Baby Weight Calculator

Find out if your baby’s weight is within a healthy range using WHO standards. Enter the age in months, sex, and current weight for a detailed percentile analysis.

This tool is informational and does not replace medical advice. Always consult your baby's pediatrician.

How does this calculation work?

Our ideal baby weight calculator uses the official growth data from the World Health Organization (WHO), the international reference for assessing child development. By entering your baby’s age in months, sex, and current weight, the system compares those values against the WHO percentile table (p3, p15, p50, p85, and p97). The 50th percentile represents the median — the most common weight for that age and sex. Values between p15 and p85 are considered within the normal range. Results below p3 or above p97 deserve attention and pediatric follow-up. Remember: every child grows at their own pace, and this tool is meant as guidance, not a replacement for medical advice.

Frequently asked questions

What is the ideal weight for a 6-month-old baby?▾
According to the WHO, the median weight (50th percentile) for a 6-month-old is approximately 7.9 kg (17.4 lbs) for boys and 7.3 kg (16.1 lbs) for girls. However, weights between the 15th and 85th percentiles are considered normal. What matters most is tracking the growth curve over time with your pediatrician.
My baby is below the 3rd percentile. Should I be worried?▾
A weight below the 3rd percentile may indicate underweight for the age, but it does not necessarily mean there is a problem. Genetic factors, prematurity, and individual growth patterns all influence weight. It is essential to discuss the complete growth history with your pediatrician and, if needed, investigate possible causes.

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