Most newborns gain about 1 ounce (28 grams) per day during their first three months, which works out to roughly 1.5 to 2 pounds per month. That pace slows steadily as your baby gets older, dropping to about half a pound per month by the end of the first year. Here’s what to expect at each stage.
Birth Through 3 Months
Before your baby starts gaining, expect a small dip. Most newborns lose 5 to 10 percent of their birth weight in the first few days as they adjust to feeding outside the womb. They typically regain that weight within 10 to 14 days.
After that initial recovery, growth is fast. At roughly 1 ounce per day, babies in this age range put on about 1.5 to 2 pounds each month. This is the most rapid weight gain your baby will experience in their entire life outside the womb. A healthy, full-term baby typically doubles their birth weight by around 4 months.
4 to 6 Months
Growth starts to taper. By 4 months, daily weight gain drops to about 20 grams (just under ¾ of an ounce). That translates to roughly 1 to 1.25 pounds per month. During this same period, babies grow about half an inch to 1 inch in length each month, and their head circumference increases by about half an inch monthly.
You may also notice growth becoming less steady. Babies don’t gain weight in a perfectly smooth line. They tend to have bursts of rapid gain followed by quieter stretches, which is completely normal.
6 to 12 Months
By 6 months, many babies are gaining 10 grams or less per day, which comes out to roughly half a pound to 1 pound per month. This slowdown is expected and happens even as babies start eating solid foods. It reflects a natural shift: your baby is now burning more calories through crawling, sitting up, and exploring, so less energy goes toward pure weight gain.
By their first birthday, most babies have tripled their birth weight. Boys tend to hit this milestone around 13 months, while girls reach it closer to 15 months.
Quick Reference by Age
- 0 to 3 months: about 1.5 to 2 pounds per month (28 grams/day)
- 4 to 6 months: about 1 to 1.25 pounds per month (20 grams/day)
- 6 to 12 months: about 0.5 to 1 pound per month (10 grams/day or less)
Breastfed vs. Formula-Fed Babies
Breastfed and formula-fed babies follow slightly different growth curves. In the first three months, their weight gain is similar. After that, formula-fed infants typically gain weight more quickly. Breastfed babies tend to be leaner through the first year overall, and this difference persists even after solid foods are introduced.
Both patterns are healthy. The important distinction is that the CDC recommends using WHO growth charts for all children under 2, and those charts are based on breastfed infants. If your baby is formula-fed and tracking above the 50th percentile, that doesn’t necessarily mean they’re gaining too much. It just reflects the normal difference between feeding methods. Length growth, notably, is similar regardless of how a baby is fed.
Growth Spurts
Your baby won’t gain weight at a perfectly predictable rate. Growth spurts cause temporary jumps in appetite and weight gain, and they tend to cluster around specific ages: 2 to 3 weeks, 6 weeks, 3 months, 6 months, and 9 months. During a spurt, your baby may want to feed more frequently, seem fussier than usual, and sleep differently. These episodes typically last a few days to a week before settling back to normal.
Premature Babies Gain Differently
If your baby was born early, standard weight gain timelines don’t apply directly. Premature infants (over about 4.4 pounds) are expected to gain 20 to 30 grams per day in the early months, which is comparable to full-term newborns. But their growth is tracked using “corrected age,” the age they would be if born at their due date, rather than their actual birth date.
The most significant catch-up growth happens in the weeks around what would have been the due date. Most preemies close the gap with full-term peers by 12 to 18 months of corrected age, though some continue catching up for several years. The goal isn’t always to reach the same percentile as a full-term baby. For some preemies, especially those who were small for gestational age, following a consistent curve on the growth chart matters more than hitting a specific percentile.
Signs of Slow Weight Gain
Pediatricians track your baby’s growth at every well-child visit by plotting weight, length, and head circumference on standardized growth charts. A single weigh-in that seems low isn’t usually a concern. What matters is the pattern over time. A baby who consistently drops across percentile lines, rather than following their own curve, may need evaluation.
Signs you might notice at home include excessive sleepiness (especially falling asleep during feedings before finishing), crying more than expected, and not engaging socially the way other babies their age do, such as mimicking your facial expressions. Fewer than six wet diapers a day in the early months can also signal that a baby isn’t getting enough to eat. These signs don’t automatically mean something is wrong, but they’re worth bringing up with your pediatrician, who can look at the full picture alongside the growth chart.