Child Growth Calculator Guide
What is the Child Growth Calculator?
The Child Growth Calculator compares your child's measurements against World Health Organization (WHO) growth reference medians for their age and sex. It provides a general guide to whether your child's weight and height are within expected ranges.
How to calculate it manually
BMI-for-age = weight (kg) ÷ height² (m²). Compare to WHO median weight for the child's age and sex using a Z-score approach. A Z-score between −2 and +1 is generally within the normal range.
Frequently Asked Questions
A child at the 75th percentile for weight is heavier than 75% of children of the same age and sex. Any value between the 5th and 95th percentile is generally considered within the normal range.
No. Consistent growth over time is what matters most, not the absolute percentile. A child who has always been at the 10th percentile is growing normally if their curve is steady.
If your child is below the 3rd or above the 97th percentile, if their growth has crossed two major percentile lines, or if you have any concerns, speak to a paediatrician.
This tool uses approximate WHO Child Growth Standards medians as reference data. For clinical assessment, your doctor uses detailed WHO or national growth charts with full percentile bands.