Early 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: