Baby Growth Percentile (0‑24 Months)

How to Use Baby Growth Percentile

1. Select your baby’s gender. Choose boy or girl, as growth standards differ between the two.
2. Enter your baby’s age. Input age in months (0–24), using decimals for partial months, e.g. 6.5 for six and a half months.
3. Provide weight and length. Enter your baby’s current weight in kg and length in cm, measured as accurately as possible.
4. Click Calculate. The tool compares the values against simplified WHO growth charts and shows which percentile band your baby falls into for weight and length.

Benefits of Baby Growth Percentile

• Uses WHO child growth standards, the globally recognised reference for healthy infant development from 0–24 months.
• Shows both weight and length percentiles so you can track whether your baby is proportionate.
• Gives a straightforward band (e.g. 15th–50th) rather than an overly precise number, which better reflects clinical interpretation.
• Completely private – no baby data is stored or shared, and the tool runs offline in your browser.

Frequently Asked Questions

What does it mean if my baby is in the 3rd percentile?

It means that out of 100 babies of the same age and gender, about 3 weigh less. This can be normal for a small but healthy baby, but your paediatrician should monitor growth trends over time.

Is a higher percentile always better?

Not necessarily. What matters most is consistent growth along the same percentile curve, not the absolute number. A baby who stays on the 25th percentile is growing well.

Can I use this calculator after 24 months?

No, this tool is built for the 0–24 month age group. For children over 2 years, use a CDC or IAP growth chart. The BMI calculator for kids is available on Toolzo for ages 2–18.

Is Baby Growth Percentile free and private?

Yes — it is 100% free, needs no sign‑up, and everything runs in your browser; your data never leaves your device.