Newborn Measurements

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. 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).

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

Like weight, length and head circumference help your baby's healthcare 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. The distance around the baby's head:

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

  • Generally, a newborn's head is about half the baby's body length in cm plus10 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. 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 in long.