Most 2-month-old babies weigh between 9 and 13 pounds, with the average falling around 11 to 12 pounds for boys and 10 to 11 pounds for girls. But the number on the scale matters less than your baby’s overall growth pattern, because a healthy 2-month-old who was born at 6 pounds will look very different from one who was born at 9 pounds.
Average Weight at 2 Months
The World Health Organization growth charts, which the CDC recommends for all infants from birth to age 2, place the 50th percentile for 2-month-old boys at roughly 12.3 pounds (5.6 kg) and for girls at roughly 11.3 pounds (5.1 kg). These charts were built from data on healthy children in six countries, including the U.S., raised in conditions that support optimal growth.
That said, the 50th percentile is just the midpoint. A baby tracking along the 15th percentile is not a cause for concern as long as they stay on that curve consistently. What pediatricians watch for is the trajectory: a baby who drops from the 60th percentile to the 15th percentile over a short period is more worrying than a baby who has been steadily at the 15th since birth.
How Much Weight Babies Gain in the First 2 Months
In the first few months of life, babies gain about 1 ounce (28 grams) per day, according to the Mayo Clinic. That works out to roughly 5 to 7 ounces per week. Most newborns lose a small amount of weight in the first few days after birth (up to 7 to 10 percent of their birth weight is considered normal) and then regain it by about 10 to 14 days old. From there, steady daily gains are the expectation.
By 2 months, many babies have gained 3 to 5 pounds over their birth weight. A baby born at 7.5 pounds, for example, might weigh somewhere around 11 to 12 pounds at their 2-month checkup. Babies typically double their birth weight by around 4 to 5 months, so at 2 months they’re roughly on the way to that milestone but not there yet.
Breastfed vs. Formula-Fed Babies
Growth patterns differ depending on how your baby is fed. Breastfed infants typically put on weight more slowly than formula-fed infants during their first year, according to the CDC. The difference becomes more noticeable after about 3 months, when formula-fed babies tend to gain weight more quickly. These differences persist even after solid foods are introduced later on.
This means a breastfed 2-month-old on the lighter side of the growth chart is not necessarily behind. The WHO growth charts were developed primarily from breastfed infants, which is one reason the CDC recommends them for this age group. If your pediatrician is using these charts, your breastfed baby’s weight is being compared against an appropriate reference population.
Birth Weight and Prematurity Matter
Your baby’s starting point shapes where they’ll be at 2 months. A baby born at 6 pounds and growing steadily will naturally weigh less at 2 months than a baby born at 9 pounds, and both can be perfectly healthy. Genetics play a significant role too. Parents who are smaller in stature often have babies who track along the lower percentiles.
For premature babies, the expected weight at 2 months looks different because pediatricians use “corrected age” rather than actual age. To calculate corrected age, you take the baby’s actual age in weeks and subtract the number of weeks they were born early. If your baby was born at 34 weeks (6 weeks early) and is now 2 months old, their corrected age is only about 2 weeks. Their weight should be compared against growth charts for a 2-week-old, not a 2-month-old. To figure out how many weeks early your baby was, subtract their gestational age at birth from 40 weeks.
Growth Spurts Around 2 Months
Babies go through several growth spurts in their first year, and around 6 weeks is a common one. The next typical spurt hits around 3 months. During these short bursts, your baby’s weight and length increase rapidly over a few days. You may notice your baby wanting to eat more frequently, or sometimes less. Fussiness and extra clinginess are also common signs.
If your 2-month-old suddenly seems insatiable, a growth spurt is a likely explanation. Offering extra feedings during this period helps your baby get what they need. Growth spurts are temporary and usually resolve within a few days.
Signs of Slow Weight Gain
Most babies grow at their own pace without any issues, but some signs suggest a baby may not be gaining enough weight. These include sleeping more than expected (or falling asleep during feedings), crying more than usual, and not engaging socially the way you’d expect for their age, such as mimicking facial expressions.
A more concrete way to track adequate intake in newborns and young infants is wet diapers. By the end of the first week, your baby should be producing at least six wet diapers a day. Fewer than that can signal they aren’t getting enough milk or formula. At the 2-month well-child visit, your pediatrician will plot your baby’s weight and length on a growth chart and compare it against previous measurements. A single low reading is rarely alarming on its own. A pattern of declining percentiles, where a baby is consistently falling further from their established curve, is what triggers closer monitoring.
Growth faltering (sometimes called failure to thrive) is identified by comparing a child’s weight and length against standardized growth charts over time. It can have many causes, from feeding difficulties to underlying health conditions, and is typically caught at routine checkups before it becomes a serious problem.