From the Pregnancy, Birth & Baby website
My personal recommendation to you is to take everything you hear and read with a grain of salt. In other words, every baby is individual. There are no two identical mommies. You and your baby are unique. This includes everything about you. Looking at a weight chart can give you an idea of where you and baby fit in the averages. But not being there immediately does not mean there is a problem. Do not obsess on individual characteristics in your babies life. It is the combination of many different criteria that show good development. Proper development includes many areas. Some are larger, some have hair, some do not, some are smaller, longer, lighter or darker. If your baby is happy, eating well, putting on weight, sleeping reasonably well, and advancing developmentally than you are doing well. Step back and look at the whole picture. Talk to other new moms, your friends and family. Enjoy every moment of this precious time. It will be gone in and instant.
Understanding baby growth charts
As the name suggests, baby or infant growth charts indicate how your child is growing. It’s important not to compare your baby’s size with that of other babies since this may be misleading. The most important thing is that your baby is healthy, happy and growing appropriately.
What is an infant growth chart?
An infant growth chart helps you, your doctor and other health professionals keep track of how your baby is growing. There are different charts for boys and girls, for infants and for older children.
Growth charts record changes in your baby’s length, weight and head circumference. These measurements are marked down on the chart so you can see how they change over time. On the vertical (up-and-down) axis is the measurement; on the horizontal (side-to-side) axis is the baby’s age.
There will probably be a growth chart in your child’s personal health record (often called the blue, red or green book, depending on which state you live in). Your child and family health nurse or GP may also keep a birth chart for your baby.
All babies grow at different rates, and ‘normal’ growth ranges a lot. As long as your baby continues to grow, is responsive and is healthy, there’s usually no need to worry about the trend on the growth chart.
How to understand percentiles
Infant growth (aged 0 to 2) 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.
Most states and territories use charts from the US Centers for Disease Control to measure growth and weight in children and adolescents aged 2 to 18 years.
Like adults, babies come in all shapes and sizes. The growth charts show this by using ‘percentiles’. A baby on the 50th percentile for weight, for example, is right in the middle of the normal range: 50% of babies their age are lighter, and 50% are heavier. A baby on the 5th percentile weighs less than 95% of other babies of that age. A baby on the 90th percentile weights more than 90% of other babies that age.
Some babies will always be small and others will always be large. The important thing is that they are growing as expected for their percentile. The charts help you track this by showing normal growth curves (i.e. always increasing). You can plot your baby’s growth to see if it follows a similar pattern to other babies on that percentile.
How will my baby be measured?
Your baby will be weighed and measured at birth. After that, repeating the measurements once a month or so is usually enough to track how they are growing. Don’t worry if their weight goes up and down from day to day – this is normal.
Babies under 2 years old are usually weighed on a special infant scale (newborns will lie down on the scale). It’s more accurate to weigh babies with no clothes on until they are 12 months. After they turn 2, they can be measured standing up in light clothes. You baby’s head circumference will be measured using a tape measure.
If your child was born prematurely, their age needs to be ‘corrected’ (age adjusted to take into account the weeks they are premature by subtracting these from the age from birth) on the chart until they turn 2 years old.
Growth charts can actually be used until your child turns 18. Your child health nurse or GP can tell you what other health checks are needed to make sure your child is growing and developing normally.
When should I be worried?
Parents are often worried that their baby isn’t growing fast enough. However, while it’s important to measure a child’s growth to see if they are healthy and developing properly, it’s not the only way to tell if they’re healthy.
All babies lose some weight in the week after birth and regain this weight by 2 weeks. Most babies double their birth weight by 4 months and triple it by 13 months (for boys) or 15 months (for girls).
There is unlikely to be anything wrong if your baby:
- has at least 5 very wet nappies each day
- has pale wee
- does well-sized, soft poos
- has good skin colour and muscle tone
- is meeting other developmental milestones
Weight gain can be affected by an infection or vomiting. If you are ever worried, talk to your child and family health nurse or GP.
If your child’s percentile changes significantly – for example, if they drop by 2 percentile lines – then talk to your child and family health nurse or GP. They will assess the child’s growth trend to see if there is any reason to be worried.
Remember, don’t compare your child’s growth to that of other kids. The important thing is that they continue growing following the same percentile.
Where to go for help
If you have any questions about your baby’s growth or development, you can call Pregnancy, Birth and Baby on 1800 882 436. Or, see your child’s doctor or early childhood nurse.
Victoria Government Maternal and Child Health Services (Growth charts), Raising Children Network (Child growth charts), The Conversation (Our obsession with infant growth charts may be fuelling childhood obesity), Australian Breastfeeding Association (Baby weight losses and weight gains), NSW Health (Blue Book), The Royal Children’s Hospital Melbourne (Top 10 things you need to know about growth charts), World Health Organization (Child growth standards)
Learn more here about the development and quality assurance of healthdirect content.
Last reviewed: February 2020
Understanding baby size
Babies come in all shapes and sizes. Weight can vary drastically. The average weight for full-term babies is 7 pounds, 5 ounces. However, a percentage of healthy, full-term babies are born under or over that average weight.
As your baby grows, their rate of weight gain will be an important indicator of overall health and development. Your baby’s pediatrician will monitor weight, length, and head size at each well-child appointment to determine if your baby is progressing as they should.
Read on to learn more about the average weights for different ages
Chart of average baby weights
The following weights for maleTrusted Source and femaleTrusted Source babies are from the World Health Organization (WHO). Both the Centers for Disease Control and Prevention (CDC) and American Academy of Pediatrics recommend using WHO’s charts for children up to 2 years old.
Here’s a break down. Trusted Source for the first year:
|Age||50th percentile weight for male babies||50th percentile weight for female babies|
|Birth||7.8 lbs. (3.5 kg)||7.5 lbs. (3.4 kg)|
|0.5 months||8.8 lbs. (4.0 kg)||8.4 lbs. (3.8 kg)|
|1.5 months||10.8 lbs. (4.9 kg)||9.9 lbs. (4.5 kg)|
|2.5 months||12.6 lbs. (5.7 kg)||11.5 lbs. (5.2 kg)|
|3.5 months||14.1 lbs. (6.4 kg)||13 lbs. (5.9 kg)|
|4.5 months||15.4 lbs. (7.0 kg)||14.1 lbs. (6.4 kg)|
|5.5 months||16.8 lbs. (7.6 kg)||15.4 lbs. (7.0 kg)|
|6.5 months||18 lbs. (8.2 kg)||16.5 lbs. (7.5 kg)|
|7.5 months||19 lbs. (8.6 kg)||17.4 lbs. (7.9 kg)|
|8.5 months||20.1 lbs. (9.1 kg)||18.3 lbs. (8.3 kg)|
|9.5 months||20.9 lbs. (9.5 kg)||19.2 lbs. (8.7 kg)|
|10.5 months||21.6 lbs. (9.8 kg)||19.8 lbs. (9.0 kg)|
|11.5 months||22.5 lbs. (10.2 kg)||20.7 lbs. (9.4 kg)|
|12.5 months||23.1 lbs. (10.5 kg)||21.4 lbs. (9.7 kg)|