Baby Growth Calculator

Check whether your baby's weight and height are on track with WHO growth standards. Enter age, weight, and length for instant percentile feedback.

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How Baby Growth Is Measured

Baby growth is tracked using percentile charts based on WHO (World Health Organization) growth standards. A percentile tells you how your baby compares to a reference population: a baby at the 50th percentile is exactly average; the 25th percentile means 25% of babies that age weigh less and 75% weigh more. No single percentile is “correct” — what matters is consistent growth along a similar curve over time.

What the Percentiles Mean

Any percentile between the 3rd and 97th is generally considered within the normal range. Concern arises when a baby falls below the 3rd percentile, crosses two or more percentile lines downward over several months, or shows a sudden change in growth trajectory. Your paediatrician evaluates these trends in context with family history, feeding, and development.

Factors That Affect Baby Growth

Genetics is the strongest determinant of growth — tall parents tend to have taller babies. Feeding method (breastfed vs. formula-fed), birth weight, gestational age, and overall health all influence growth patterns. Premature babies use an adjusted age (actual age minus weeks premature) for growth chart comparisons.

Frequently Asked Questions

Is a higher percentile better?
Not necessarily. A baby consistently at the 10th percentile is growing normally for their genetic potential. What matters is consistency — not the percentile number itself.
When should I be concerned about my baby’s growth?
Discuss with your doctor if your baby falls below the 3rd percentile, drops across two major percentile lines, or if their weight gain has significantly slowed or stopped between check-ups.
How often should babies be weighed?
Newborns are typically weighed at birth, at 5 days, 10–14 days, and then monthly for the first year. At routine health checks your doctor or nurse will plot measurements on a growth chart.
Medical Disclaimer: This calculator is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for health decisions.