Track your baby's growth and development with percentile calculations based on WHO growth standards. Monitor weight, length, and head circumference from birth to 24 months.
Enter age in months (0-24 months)
Growth percentiles compare your baby's measurements to other babies of the same age and sex. They help healthcare providers track development and identify potential growth concerns early.
If your baby is in the 50th percentile for weight, it means 50% of babies the same age weigh less, and 50% weigh more. Percentiles range from 1st to 99th, with most babies falling between the 5th and 95th percentiles.
A single percentile measurement is less important than the growth pattern over time. Consistent growth along a percentile curve is healthy, even if it's at the 10th or 90th percentile. Sudden changes or crossing multiple percentile lines may warrant medical attention.
Our calculator uses World Health Organization (WHO) growth standards, which are based on healthy, breastfed babies from diverse populations worldwide. These standards represent optimal growth under ideal conditions.
Babies typically lose 5-10% of birth weight in the first week, then regain it by 2 weeks. Average weight gain:
Length is measured lying down until age 2, then height standing up. Average growth:
Head circumference reflects brain growth and development. Average growth:
Parents' heights and builds significantly influence baby's growth patterns. Tall parents typically have taller babies, while shorter parents have smaller babies. This is normal variation, not a concern.
Breastfed and formula-fed babies may have different growth patterns. Breastfed babies often gain weight more slowly after 3-4 months but are leaner. Both patterns are healthy when babies are thriving.
Premature babies are plotted using corrected age (adjusted for prematurity) until age 2-3. They often catch up to full-term peers by age 2, though some remain smaller.
Chronic illnesses, feeding difficulties, reflux, or metabolic disorders can affect growth. Consistent monitoring helps identify issues early for timely intervention.
While percentiles are useful tools, they're just one part of assessing your baby's health. Contact your pediatrician if you notice:
Sudden drops or jumps crossing two or more percentile lines, or consistently falling percentiles over several months may indicate feeding issues or health concerns.
Measurements consistently below the 3rd percentile or above the 97th percentile warrant evaluation, especially if accompanied by other symptoms or developmental delays.
Poor feeding, excessive spitting up, refusing bottles or breast, or taking very long to feed may affect growth and should be addressed.
If growth issues are accompanied by missed developmental milestones, lethargy, or other symptoms, medical evaluation is important.
Weigh baby naked or in a dry diaper at the same time of day, preferably before feeding. Use a baby scale for accuracy, as adult scales may not be precise enough for small weight changes.
Lay baby flat on their back with legs straight. Measure from the top of the head to the bottom of the heel. This is easier with two people—one to hold baby still and one to measure.
Use a flexible measuring tape around the largest part of the head, just above the eyebrows and ears, and around the back where the head slopes up from the neck. Take the measurement three times and use the largest.
For tracking growth over time, try to measure under similar conditions each time. Professional measurements at pediatric visits are most accurate for percentile tracking.
Most babies between the 5th and 95th percentiles are perfectly healthy. What matters most is consistent growth along their own curve, not the specific percentile number.
Small fluctuations are normal, but dropping two or more percentile lines or consistently falling percentiles warrants discussion with your pediatrician to rule out feeding issues or health concerns.
Pediatricians typically measure growth at well-child visits: frequently in the first months, then at 6, 9, 12, 15, 18, and 24 months. You don't need to measure at home unless advised by your doctor.
Yes, breastfed babies often gain weight more rapidly in the first 3-4 months, then more slowly afterward. Formula-fed babies may have steadier weight gain. Both patterns are healthy.
Most premature babies catch up to their full-term peers by age 2-3, though some remain smaller. Growth is tracked using corrected age (adjusted for prematurity) until age 2-3.
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