Pediatric Health Library

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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. 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?

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.

Online Medical Reviewer: Donna Freeborn PhD CNM FNP
Online Medical Reviewer: Heather M Trevino BSN RNC
Online Medical Reviewer: Liora C Adler MD
Date Last Reviewed: 3/1/2022
© 2000-2024 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.