If you are concerned about your baby’s development, we are here to help you out. What is the average weight and length for babies, and when to seek help from healthcare? Your doctor will measure your baby every time you visit. For example, they will measure your baby’s head circumference, which signals if there is an issue in their brain development.
General information
Having a child is something special; however, the huge responsibility can sometimes make you worry. Many of you may be wondering if your baby is big enough or too small for their age. Without further ado, let’s get the basics straight.
The average of a newborn in the United States is 3.3 kg. In general, girls weigh about 3.2 kg at birth, while baby boys are slightly bigger, weighing 3.3 kg. The average length of a newborn is 49,5 cm, with girls measuring 49 cm and boys about 50 cm.
It is normal for babies to lose weight during their first couple of days after being born. However, in the first few weeks of life, they should reach their birth weight again. After four months of life, babies would usually double their weight, and after one year, even triple their weight. A baby would normally gain an ounce every day until they reach three months. Another thing to keep in mind is that most babies grow 25 cm until their first year.
To help you understand the process better, read the guidelines below based on the data from the World Health Organization. Before we move forward, please keep in mind the upcoming information is just a benchmark. It is normal for infants to have growth spurts; therefore, don’t be quick to worry about their growth process. What matters the most is for your baby to grow consistently.
Please note that for prematurely born babies, you should consider the gestational age. If you have a baby with special needs, consult your doctor for specific measurements.
Boys average weight and length up to one year
A newborn baby boy usually weighs about 3.3 kg and measures 49.9 cm. However, there is no need to worry if your baby is slightly smaller or bigger unless your doctor says otherwise. A month old baby weighs 4.5 kg and measures 54,7 cm. At two months, average baby boys reach 5,6 kg and grow up to 57.9 cm in length. Three-month-old baby boys weigh 6.4 kg and have 60.8 cm.
They reach 63.9 cm in length and 7 kg in four months; at five, they gain 5 grams more and reach about 65.9 cm. At six months, babies weigh 7.9 kg and measure 67.6 cm; at seven, they reach 8.3 kg and 69.2 cm. By the eight-month of life, the baby gains extra 3 grams and reach 70.6 cm in length.
They weigh 8.9 kg and are 72 cm; at nine months, then, 9.2 kg and 73.3 cm in the following month. By the eleventh month, the baby will weigh 9.4 kg and 74.5 cm, respectively 9.6 kg and 75.7 cm after one year of life.
Girls average weight and length up to one year
A newborn baby girl usually weighs about 3.2 kg and measures 49.1 cm. A month old baby weighs 4.2 kg and measures 53.7 cm. At two months, average baby girls reach 5.1 kg and grow up to 57.1 cm in length. Three-month-old baby boys weigh 5,8 kg and have 59.8 cm.
They reach 62.1 cm in length and 6,4 kg in four months; at five, they gain 5 grams more and reach about 64 cm. At six months, babies weigh 7.3 kg and measure 65.7 cm; at seven, they reach 7.6 kg and 67.3 cm. By the eight-month of life, the baby gains extra 3 grams and reach 68.7 cm in length.
They weigh 8.2 kg and are 70.1 cm; at nine months, then, 8.5 kg and 71.5 cm in the following month. By the eleventh month, the baby girl will weigh 8.7 kg and 72.8 cm, respectively 8.9 kg and 74 cm after one year of life.