Baby Weight Percentile Calculator
Where your baby's weight sits.
Enter your values
ⓘ Live results
Results
- Estimated percentile
- 37.1%
- Median weight for age
- 7.9 kg
- Z score
- -0.33
- Difference from median
- -0.3 kg
- Interpretation
- Within typical range
Quick answer
A weight percentile shows the share of babies of the same age and sex who weigh less than yours.
How to use the Baby Weight Percentile Calculator
- 1Enter your baby's age in whole months (0–12).
- 2Enter weight in kilograms.
- 3Select boy or girl.
Worked example
Using the values the calculator loads with:
Inputs
- Age6 months
- Weight7.6 kg
- SexBoy
Results
- Estimated percentile37.1%
- Median weight for age7.9 kg
- Z score-0.33
- Difference from median-0.3 kg
- InterpretationWithin typical range
Frequently asked questions
Is a low percentile a problem?
Not on its own — steady growth along a curve matters more than the number.
Is this a medical tool?
No, it is an estimate; your paediatrician uses the full WHO tables.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.