Newborn Measurements

Assessing a newborn's weight

A baby's birth weight is an important indicator of health. The average weight for full-term babies (born between 37 and 41 weeks' gestation) is about 7 pounds (3.2 kg). In general, small babies and very large babies are more likely to have problems. Newborn babies may lose as much as 10% of their birth weight during the first 5 days after birth. This means that a baby weighing 7 pounds 3 ounces at birth might lose as much as 10 ounces in the first few days.

Your newborn will be weighed in the hospital and at all check-ups. In most cases, metric units are used to record babies' weight. This chart will help you convert the metric unit grams (g) to pounds (lb) and ounces (oz).

Converting grams to pounds and ounces

1 lb. = 453.59237 grams; 1 oz. = 28.349523 grams; 1000 grams = 1 kg.

What other measurements are taken of the newborn?

Measurements like weight, length, and head circumference help your baby's health care provider get an idea of their overall health. They may also be measured using metric units, with centimeters (cm) instead of inches (in). To convert inches to centimeters: 1 in = 2.54 cm.

• Head circumference. This is the distance around the baby's head.

  • The average newborn's head measures 13 3/4 inches (35 cm).

  • Generally, a newborn's head is about half the baby's body length in cm plus 10 cm. So a baby that's 18 inches long would be 45.7 centimeters (18 x 2.54). Their head would be about 32.9 cm, or a little under 13 inches.

• Length. This is the measurement from the top of the head to the heel of the foot.

  • The average newborn is about 50 cm or 19 3/4 inches long.