From birth your baby needs to be breastfed or formula fed regularly to have good weight gain.
It’s a good idea to have your baby’s weight checked regularly. This helps make sure they are healthy, growing and feeding well.
Babies are usually weighed:
- at birth
- during their first 2 weeks
- once a month up to 6 months
- every 2 months from 6 to 12 months
- every 3 months after their first birthday
What affects your baby's birth weight
Your baby’s birth weight will depend on how close they were born to their due date. Babies born after their due date are often larger. Those babies born before their due dates are often smaller.
Your baby’s birth weight can also be affected by:
- birth order — first babies can be smaller than future siblings
- gender — male babies are often larger
- baby's health when born
- babies of multiple births are often smaller
- parents’ height and weight
- mother’s health and diet before and after birth
If your baby is born underweight or overweight, they may be monitored more closely to check for possible problems.
The first months
It is normal for babies to lose some weight after they are born.
Healthy babies normally lose anything up to 10% of their birth weight in the first week after being born.
Healthy babies usually get back to their birth weight in 2 to 3 weeks with regular feeding.
It is normal for breastfed babies to receive small amounts of colostrum in their first few days. The breastfeeding parent then begins making breastmilk that provides all the nutrients they need to help them grow.
General guidelines for growth
All babies grow differently but there are guidelines for healthy weight gain.
A useful guide is that most healthy, full-term newborn babies double their birth weight by 4 months.
A boy's weight will triple in about 13 months. A baby girl's weight will triple in about 15 months. However, all babies grow at their own pace.
Infant growth (aged 0 to 2 years) is usually calculated using the World Health Organization's (WHO) growth standards. Infant growth charts allow health professionals to compare your baby's growth with that of all other babies of the same age.
Your baby's growth records
Weighing your baby regularly helps you know if they are healthy, growing and feeding well.
Your baby’s weight and other measurements will be recorded in your baby’s health record, by your healthcare practitioner.
This record helps health professionals check your baby’s growth and development against what would be expected.
Your baby’s weight and length will be plotted on a graph that shows normal weights and lengths for babies at different ages. This shows how your baby is growing between check-ups.
Read about your baby's developmental milestones.
Your baby’s weight gain might slow down because:
- your baby starts to sleep more and feeds less often
- you or your baby become ill
- your breastmilk supply changes (there are different reasons this might happen)
If you’re worried, see your doctor, nurse or midwife or call Pregnancy, Birth and Baby on 1800 882 436.
You can also organise a visit with a lactation consultant if you’d like extra support with breastfeeding.
Learn more here about the development and quality assurance of healthdirect content.
Last reviewed: June 2022