Baby Weight Gain Chart: How Much Should a Baby Gain?

Most babies lose a little weight after birth and are back to birth weight by about 10 to 14 days. Then they gain roughly 7 to 9 ounces a week for two months, about 5 ounces a week by 3 to 4 months, about 3 ounces by 6 months and about 2 ounces by 12 months.

Weight is one of the clearest signs your baby is eating enough, which is why it gets checked at every early visit. But healthy babies do not grow in a straight line. They gain in bursts, some weeks more and some less, and a single weigh-in tells you less than the trend over several visits.

The numbers here come from the World Health Organization (WHO) growth standards, which US pediatricians use for babies under 2.

How much weight should a baby gain per month?

The "median" is the middle baby: half gain more, half gain less. The middle 50% column shows the range where half of all healthy babies fall. Plenty of healthy babies sit outside it. These are monthly increments, and the first row includes the early dip and recovery.

How much weight do newborns lose, and when do they regain it?

Almost all newborns lose some weight in the first few days while feeding gets established. The AAP's HealthyChildren site says a baby may lose no more than about 8 to 10% of birth weight in the first days before starting to gain again.

Clinicians expect babies to be back to birth weight by about 10 to 14 days. A large 2016 study in Pediatrics of more than 140,000 newborns found that half were back to birth weight by day 9 after a vaginal birth and day 10 after a cesarean. By day 14, 86% of vaginally born babies and 76% of cesarean-born babies were back. So being a little behind at two weeks is not unusual, but your pediatrician will want to follow it closely.

How much weight should a baby gain in the first month?

Measured from birth, the WHO median gain for the first four weeks is about 31 ounces (879 g) for girls and 36 ounces (1,023 g) for boys, roughly 2 pounds. Because that includes the early loss, most of the gain happens in weeks 2 to 4, once milk is in and feeding is steady.

Texas Children's Hospital describes gain in the first three months as roughly an ounce a day on average, in bursts rather than evenly.

How much weight should a baby gain by 2 months?

Adding the WHO median monthly gains, a typical baby is about 4 pounds above birth weight by 2 months for girls and close to 5 pounds for boys. That is the fastest growth of the whole first year. Your baby may go through growth spurts along the way, with a few days of hungrier, more frequent feeds.

How much weight should a baby gain per week?

As a rough guide from the WHO medians:

• Weeks 2 to 8: about 7 to 9 ounces a week
• 2 to 3 months: about 6 ounces a week
• 3 to 4 months: about 5 ounces a week
• 4 to 6 months: about 3.5 to 4 ounces a week
• 6 to 9 months: about 2.5 to 3 ounces a week
• 9 to 12 months: about 2 ounces a week

Texas Children's notes that typical babies double their birth weight by around 6 months and triple it by 1 year.

What do weight percentiles mean?

A percentile compares your baby to a large group of healthy babies of the same age and sex. If your baby is at the 50th percentile, half of babies weigh more and half weigh less. At the 15th percentile, 85 out of 100 babies weigh more.

A few things to keep in mind:

• There is no "good" percentile. A baby at the 10th percentile can be as healthy as one at the 90th.
• The line matters more than the dot. Most babies roughly follow their own curve over time.
• Under age 2, US pediatricians use the WHO growth standards. The CDC recommends WHO charts from birth to 2 and CDC charts from age 2.
• Home scales vary. Compare weights from the same scale, with your baby undressed.

When should you worry about a baby's weight gain?

MedlinePlus, from the US National Library of Medicine, says providers look more closely when a measurement stays below the 10th or above the 90th percentile, or when growth does not follow a percentile line. For example, a drop from the 75th to the 25th percentile between 6 and 9 months would be a concern.

Call your pediatrician if:

• Your baby is not back to birth weight by about 2 weeks
• Your baby lost more than about 10% of birth weight in the first days
• Weight drops across two or more percentile lines between visits, or stays flat
• There are fewer than six wet diapers a day after the first week (see our wet diaper guide)
• Your baby is too sleepy to feed well, feeds poorly, or seems unwell

Slow gain does not always mean a problem, since some babies are naturally smaller. If gain is too slow, your pediatrician will look at feeding volume, digestion and other causes and suggest next steps. Our guide to how much a newborn should eat can help you prepare questions.

How MamaBee helps you track growth

Growth makes more sense as a line than a list of numbers. In MamaBee you can log weight, length and head size and see WHO percentiles for each entry, so you can watch your baby's curve between visits. Feeds and diapers sit on the same timeline, which helps if your pediatrician asks how feeding is going. Before a checkup, export a pediatrician PDF of the last 7 days. Our well baby visit schedule shows when growth gets measured.

Frequently asked questions

How much weight should a newborn gain per week?

After regaining birth weight at around 10 to 14 days, newborns typically gain about 7 to 9 ounces a week through the first two months, based on WHO growth standards. Weekly gain varies, so your pediatrician looks at the trend across several weigh-ins.

How much weight should a baby gain in the first month?

Measured from birth, the WHO median gain for the first four weeks is about 31 ounces for girls and 36 ounces for boys, roughly 2 pounds. This includes the small weight loss in the first days, so most of the gain comes in weeks 2 to 4.

When should a baby be back to birth weight?

Clinicians expect babies to regain birth weight by about 10 to 14 days. In a large study, half of newborns were back by day 9 or 10, and most by day 14. If your baby is not back by two weeks, your pediatrician will want to check feeding and weight closely.

Is it bad if my baby is in a low percentile?

Not by itself. A baby who steadily follows a low percentile line can be perfectly healthy. Pediatricians look more closely when a baby stays below the 10th percentile, or drops across percentile lines over time.

When do babies double their birth weight?

Typical babies double their birth weight by around 6 months and triple it by their first birthday.

The takeaway

Expect a small dip after birth, a return to birth weight by about two weeks, then roughly 7 to 9 ounces a week for the first two months, slowing steadily through the first year. Watch the curve, not one number, and call your pediatrician if your baby is slow to regain birth weight or drops across percentile lines.

Sources: WHO: Weight Velocity Standards, Paul et al., Weight Change Nomograms for the First Month After Birth (Pediatrics, 2016), CDC: Growth Charts, MedlinePlus: Growth Charts, Texas Children's: Baby Weight Gain Guide, AAP HealthyChildren: How to Tell if Baby Is Getting Enough Milk

This article is general information, not medical advice. Always check with your pediatrician about your baby.