Baby Growth Percentile
Track your baby's growth based on WHO standards
Baby Information
Birth to 24 months
Enter measurements to see percentile results
Understanding Percentiles
A percentile shows where your baby falls compared to other babies of the same age and sex. For example, a 50th percentile weight means your baby weighs more than 50% of babies that age.
Frequently Asked Questions
What is a baby growth percentile?
A baby growth percentile shows how your baby's measurements compare to other babies of the same age and sex. For example, if your baby is in the 75th percentile for weight, they weigh more than 75% of babies their age. Percentiles are based on data from millions of healthy children worldwide.
What percentile is considered normal for babies?
Most healthy babies fall between the 3rd and 97th percentiles. The "normal" range is typically considered 10th to 90th percentile. However, what's most important is that your baby follows their own growth curve consistently over time, not the specific percentile number.
When should I be concerned about my baby's percentile?
Consult your pediatrician if your baby is below the 3rd or above the 97th percentile, if there's a sudden drop or spike crossing two percentile lines, or if your baby's growth pattern changes dramatically. Consistent growth along any percentile curve is generally healthy.
What are WHO growth charts?
WHO (World Health Organization) growth charts are international standards developed from studying healthy breastfed babies from diverse populations. They describe how healthy children should grow under optimal conditions and are recommended for children from birth to 2 years.
How often should I measure my baby's growth?
Pediatricians typically measure babies at well-child visits: every 2-3 months in the first year, then every 3-6 months from ages 1-2. More frequent measurements may be needed if there are growth concerns. Avoid daily or weekly measurements as normal fluctuations can cause unnecessary worry.
How to Use This Calculator
Track your baby's growth and compare their measurements to WHO international standards with these simple steps:
- Select your baby's gender -- choose Boy or Girl, as growth standards differ between sexes. Boys and girls follow different median values for weight, height, and head circumference.
- Enter your baby's age in months -- input the age from 0 (birth) to 24 months. The calculator interpolates between standard data points for precise results at any age.
- Choose your measurement units -- select Metric (kilograms and centimeters) or Imperial (pounds and inches) based on your preference.
- Enter measurements -- input your baby's weight, height or length, and head circumference. You can enter any combination; all three are not required.
- Review percentile results -- each measurement displays a percentile score, a visual progress bar, and an interpretation message indicating whether the value falls within the normal range.
Understanding Baby Growth Percentiles
What Are Growth Percentiles?
Growth percentiles compare your baby's measurements to a reference population of healthy children of the same age and sex. A percentile indicates what proportion of the reference group your baby's measurement exceeds. For example, if your baby is at the 60th percentile for weight, they weigh more than 60 percent of babies their age and sex. Percentiles are not grades or scores. A baby at the 25th percentile is not "worse" than one at the 75th percentile; both can be perfectly healthy as long as they follow a consistent growth curve.
WHO Growth Standards
The World Health Organization (WHO) growth standards used in this calculator were developed from the Multicentre Growth Reference Study, which collected data from healthy breastfed infants in six countries across five continents. These standards describe how children should grow under optimal conditions and are recommended by pediatric organizations worldwide for children from birth to 2 years of age. After age 2, the CDC growth charts are commonly used in the United States.
What Do Percentile Ranges Mean?
10th to 90th Percentile: Normal Range
Most healthy babies fall in this range. Consistent growth along any curve within this band is considered healthy development.
3rd to 10th or 90th to 97th Percentile: Monitor
Babies in these ranges may still be perfectly healthy but should be monitored more closely. Track the trend over multiple visits rather than focusing on a single measurement.
Below 3rd or Above 97th Percentile: Consult Your Pediatrician
Measurements in these extreme ranges warrant a conversation with your healthcare provider to rule out underlying conditions and ensure adequate nutrition and development.
When to Be Concerned
A single measurement tells only part of the story. Pediatricians look at growth trends over time rather than individual data points. Red flags include a sudden drop or spike that crosses two or more major percentile lines, consistently falling below the 3rd percentile without a known genetic or medical reason, or a significant discrepancy between weight and height percentiles (which could indicate nutritional issues). If your baby was born prematurely, your doctor may use corrected age for percentile calculations during the first two years.
Average Weight and Height Milestones (WHO Median)
The table below shows the 50th percentile (median) weight and height values from the WHO growth standards at key ages for both boys and girls.
| Age | Boys Weight (kg) | Boys Length (cm) | Girls Weight (kg) | Girls Length (cm) |
|---|---|---|---|---|
| Birth | 3.3 | 49.9 | 3.2 | 49.1 |
| 3 months | 6.4 | 61.4 | 5.8 | 59.8 |
| 6 months | 7.9 | 67.6 | 7.3 | 65.7 |
| 9 months | 9.0 | 72.0 | 8.2 | 70.1 |
| 12 months | 9.6 | 75.7 | 8.9 | 74.0 |
| 18 months | 10.9 | 82.3 | 10.2 | 80.7 |
| 24 months | 12.2 | 87.8 | 11.5 | 86.4 |
Disclaimer
This calculator uses simplified WHO growth standard data to provide approximate percentile estimates for educational purposes. Results may differ slightly from those generated by clinical software that uses the full WHO dataset with LMS parameters. Growth percentiles are one of many tools pediatricians use to assess child health and should not be interpreted in isolation. Normal growth patterns vary widely among healthy children. Always consult your pediatrician or healthcare provider for professional evaluation of your baby's growth and development.