A percentile is a comparison with a reference group, not a grade. Weight, length and head circumference are most useful when accurate measurements are plotted over time and interpreted with feeding, development, family history and health.
What does the 75th percentile mean?
A weight at the 75th percentile means that, in the reference group, about 75 in 100 children of the same age and sex weigh less and about 25 weigh more.
A higher line is not automatically better, and a lower line is not automatically a problem.
The trend matters more than one dot
Scale differences, clothing, movement and length-measuring technique can shift a result. Clinicians look at repeated, well-taken measurements and the shape of the curve. A sudden or persistent change deserves context, not a conclusion from one home measurement.
US and UK records may display growth differently
WHO standards are widely used for babies, but the exact chart, units and clinical cutoffs can differ by service and age. Prematurity may also change how age is considered. Let the clinician who knows your baby's history interpret the record.
Keep the numbers organised
Record the date, measurement, unit and where it was taken. Nerumi plots WHO standards so you can bring a clear history to an appointment; the chart does not diagnose growth concerns.
Related guides
Month-by-month guides put growth alongside feeding and development for each healthcare system.
View references and primary sources
- World Health Organization — Child Growth Standardsaccessed 2 October 2026
- US Centers for Disease Control and Prevention — Growth Chartsreviewed 2 September 2024 · accessed 2 October 2026