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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.

Pounds

Ounces 2 3 4 5 6 7 8 9
0 907 1361 1814 2268 2722 3175 3629 4082
1 936 1389 1843 2296 2750 3203 3657 4111
2 964 1417 1871 2325 2778 3232 3685 4139
3 992 1446 1899 2353 2807 3260 3714 4167
4 1021 1474 1928 2381 2835 3289 3742 4196
5 1049 1503 1956 2410 2863 3317 3770 4224
6 1077 1531 1984 2438 2892 3345 3799 4252
7 1106 1559 2013 2466 2920 3374 3827 4281
8 1134 1588 2041 2495 2948 3402 3856 4309
9 1162 1616 2070 2523 2977 3430 3884 4337
10 1191 1644 2098 2551 3005 3459 3912 4366
11 1219 1673 2126 2580 3033 3487 3941 4394
12 1247 1701 2155 2608 3062 3515 3969 4423
13 1276 1729 2183 2637 3090 3544 3997 4451
14 1304 1758 2211 2665 3118 3572 4026 4479
15 1332 1786 2240 2693 3147 3600 4054 4508

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.

Online Medical Reviewer: Marianne Fraser MSN RN
Online Medical Reviewer: Shaziya Allarakha MD
Online Medical Reviewer: Tracy C. Garrett RNC-NIC BSN
Date Last Reviewed: 1/1/2025
© 2000-2025 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.