image001Early on during their development, babies will grow at varying rates so it is important to keep in mind that the fetal weight chart only lists averages. If your baby is significantly larger or smaller on an ultrasound, this should not be cause for alarm unless your doctor says so. At the end of the pregnancy, the baby can range from under five pounds to over nine pounds. Learning the height and weight of your baby, both before birth and after birth, is essentially important for you to be sure that your baby is developing healthily.

Fetal Weight Chart

Notes: When looking at the fetal weight chart, it is important to keep in mind that length measurements are measured differently at different stages in development. Until the baby is twenty weeks, it is measured from his crown to rump because his legs will still be curled up, making them hard to measure. After twenty weeks, however, the legs are easier to measure as they uncurl so the length after this point reflects the distance from head all the way to the toes.

Pregnancy week

Length (cm)

Mass (g)

Length (inches)

Weight (ounces)

8

1.6 cm

1 gram

0.63 inches

0.04 ounces

9

2.3 cm

2 grams

0.90 inches

0.07 ounces

10

3.1 cm

4 grams

1.22 inches

0.14 ounces

11

4.1 cm

7 grams

1.61 inches

0.25 ounces

12

5.4 cm

14 grams

2.13 inches

0.49 ounces

13

7.4 cm

23 grams

2.91 inches

0.81 ounces

14

8.7 cm

43 grams

3.42 inches

1.52 ounces

15

10.1 cm

70 grams

3.98 inches

2.47 ounces

16

11.6 cm

100 grams

4.57 inches

3.53 ounces

17

13 cm

140 grams

5.12 inches

4.94 ounces

18

14.2 cm

190 grams

5.59 inches

6.70 ounces

19

15.3 cm

240 grams

6.02 inches

8.47 ounces

20 (crown to rump)

16.4 cm

300 grams

6.46 inches

10.58 ounces

20 (crown to heel)

25.6 cm

300 grams

10.08 inches

10.58 ounces

21

26.7 cm

360 grams

10.51 inches

12.70 ounces

22

27.8 cm

430 grams

10.94 inches

15.17 ounces

23

28.9 cm

501 grams

11.38 inches

1.10 pounds

24

30 cm

600 grams

1.81 inches

1.32 pounds

25

34.6 cm

660 grams

13.62 inches

1.46 pounds

26

35.6 cm

760 grams

14.02 inches

1.68 pounds

27

36.6 cm

875 grams

14.41 inches

1.93 pounds

28

37.6 cm

1005 grams

14.80 inches

2.22 pounds

29

38.6 cm

1153 grams

15.2 inches

2.54 pounds

30

39.9 cm

1319 grams

15.71 inches

2.91 pounds

31

41.1 cm

1502 grams

16.18 inches

3.31 pounds

32

42.4 cm

1702 grams

16.69 inches

3.75 pounds

33

43.7 cm

1918 grams

17.20 inches

4.23 pounds

34

45 cm

2146 grams

17.72 inches

4.73 pounds

35

46.2 cm

2383 grams

18.19 inches

5.25 pounds

36

47.4 cm

2622 grams

18.66 inches

5.78 pounds

37

48.6 cm

2859 grams

19.13 inches

6.30 pounds

38

49.8 cm

3083 grams

19.61 inches

6.80 pounds

39

50.7 cm

3288 grams

19.96 inches

7.25 pounds

40

51.2 cm

3462 grams

20.16 inches

7.63 pounds

41

51.7 cm

3597 grams

20.35 inches

7.93 pounds

42

51.5 cm

3685 grams

20.28 inches

8.12 pounds

Watch a video to watch week-by-week fetal development:

Baby Height and Weight Chart After Birth

It is very common for a new parent to wonder if their child is developing properly, specifically how large or small they are in comparison to other children the same age. The following charts list the values of kids ranging from the 25th percentile all the way to the 75th percentile for both height and weight. Because of this, the values listed in the charts apply to half of children with a quarter being smaller than these values and a quarter being larger than them.

At every regular checkup, your child’s doctor will measure and weigh him and let you know which percentiles he fits into. If you are concerned about your child’s height or weight, talk to your doctor about it.

Notes: The information in the charts is based on the World Health Organization’s data for children younger than two years old and the U.S. Centers for Disease Control and Prevention’s data for those over two.

1. Newborn

Birth

 

Girls

Boys

Height

18.9 to 19.8 inches

19.1 to 20.1 inches

Weight

6.5 to 7.8 pounds

6.7 to 8.1 pounds

3 Months

 

Girls

Boys

Height

23.0 to 24.1 inches

23.6 to 24.7 inches

Weight

11.8 to 14.0 pounds

13.0 to 15.2 pounds

6 Months

 

Girls

Boys

Height

25.3 to 26.5 inches

26.1 to 27.2 inches

Weight

14.8 to 17.5 pounds

16.2 to 18.8 pounds

9 Months

 

Girls

Boys

Height

27.0 to 28.3 inches

27.7 to 28.9 inches

Weight

16.7 to 19.7 pounds

18.2 to 21.1 pounds

Video for newborn development:

2. Toddler

12 Months

 

Girls

Boys

Height

28.5 to 29.8 inches

29.2 to 30.5 inches

Weight

18.2 to 21.4 pounds

19.8 to 22.9 pounds

15 Months

 

Girls

Boys

Height

29.9 to 31.2 inches

30.5 to 31.8 inches

Weight

19.5 to 23.0 pounds

21.1 to 24.5 pounds

18 Months

 

Girls

Boys

Height

31.0 to 32.5 inches

31.7 to 33.1 inches

Weight

20.8 to 24.5 pounds

22.4 to 26.0 pounds

21 Months

 

Girls

Boys

Height

32.1 to 33.8 inches

32.7 to 34.3 inches

Weight

22.0 to 26.0 pounds

23.6 to 27.5 pounds

Video for toddler development: