Pregnancy Guide
NHS Choices

Your baby's weight and height

Steady weight gain is one of the signs that your baby is healthy and feeding well.

It's normal for babies to lose some weight in the first few days after birth. Your baby will be weighed during their first two weeks to make sure they regain their birth weight. Four out of five healthy babies are at, or above, their birth weight by two weeks.

Your midwife or health visitor will support if your baby loses a large amount of weight or doesn't regain their birthweight by two weeks.

They'll talk to you about how feeding is going, possibly ask to observe a feed if you're breastfeeding, and look at your baby's health in general.

How often should my baby be weighed?

After the first two weeks, your baby should be weighed:

  • no more than once a month up to six months of age
  • no more than once every two months from 6 to 12 months of age
  • no more than once every three months over the age of one

Your baby will usually only be weighed more often than this if you ask for it, or if there are concerns about their health or growth.

Your baby's length may also be measured at some of their developmental reviews.

Understanding your baby's weight chart

Your child's growth will be recorded on centile charts in their personal child health record (PCHR), or red book. These charts show the pattern of growth healthy children usually follow, whether they're breastfed or formula fed, or have a mixture of both.

Boys and girls have different charts because boys tend to be heavier and taller, and their growth pattern is slightly different.

What the centile lines mean

The curved lines on the charts are called centile lines. These show the average weight and height gain for babies at different ages.

Your baby's weight and height may not follow a centile line exactly. Their measurements may go up or down by one centile line, but it's less common for them to cross two centile lines. If this happens, your health visitor can discuss this further with you.

It's normal for your baby to be on different centiles for weight and length, but the two are usually fairly similar.

All babies are different, and your baby's growth chart won't look exactly like another baby's (even their own brother's or sister's).

Your baby's weight gain

Usually your baby will gain weight most rapidly in the first six to nine months. Their rate of growth gradually slows down as they become a toddler and are more active.

If your baby or toddler is ill, their weight gain may slow down for a while. It will usually return to normal within two to three weeks.

Your toddler's weight and height

Your child's height after the age of two can give some indication of how tall they will be when they grow up. If you like, you can use the adult height predictor in your baby's red book to work it out.

Once your child gets to the age of two, your health visitor may use their weight and height to calculate their body mass index (BMI) and plot it on a centile chart. This is a way of checking whether your child's weight is in the healthy range or not.

If they are overweight or underweight, your health visitor can give you advice about your child's diet and physical activity levels.

You can also use our BMI calculator to check your child's BMI (as long as they are two years old or over).

For more information about your baby or toddler's weight or height, talk to your health visitor or GP.


Last Updated: 08/11/2017 13:32:15