Line chart of normal weight in kg for US boys. The 50th percentile weight is 3.27 at birth, 10.15 at 1 year, 12.34 at 2 years, 14.62 at 3 years, 16.69 at 4 years, 18.67 at 5 years, 31.44 at 10 years, 56.71 at 15 years, and 68.88 at 18 years old.

Normal weight in kg for North American (USA) boys of age (in months) between birth and 18 years old. The blue line represents the mean value (50th percentile), while the upper red line represents the 90th percentile, and the lower red line the 10th percentile.
Value labels above the middle line are rounded to the kg. Values with two decimals are given in the table below.

 

Normal weight for US boys
between birth and 18 years old

Age
(Month)

Weight
(kg)

10th Percentile 50th Percentile 90th Percentile
Birth 2.78 3.27 3.82
1 3.43 4.29 5.14
3 4.78 5.98 7.14
6 6.61 7.85 9.10
9 7.95 9.18 10.49
12 8.84 10.15 11.54
18 9.92 11.47 13.05
24 10.96 12.34 14.38
30 11.77 13.52 15.71
36 12.58 14.62 16.95
42 13.41 15.68 18.15
48 14.24 16.69 19.32
54 15.10 17.69 20.50
60 15.96 18.67 21.70
66 16.83 19.67 22.96
72 17.72 20.69 24.31
78 18.62 21.74 25.76
84 19.53 22.85 27.36
90 20.45 24.03 29.11
96 21.39 25.30 31.06
102 22.34 26.66 33.22
108 23.33 28.13 35.57
114 24.38 29.73 38.11
120 25.52 31.44 40.80
126 26.78 33.30 43.63
132 28.17 35.30 46.57
138 29.72 37.46 49.61
144 31.46 39.78 52.73
150 33.41 42.27 55.91
156 35.60 44.95 59.12
162 38.03 47.81 62.35
168 40.64 50.77 65.57
174 43.34 53.76 68.76
180 46.06 56.71 71.91
186 48.69 59.51 74.98
192 51.16 62.10 77.97
198 53.39 64.39 80.84
204 55.28 66.31 83.58
210 56.78 67.78 86.14
216 57.89 68.88 88.41

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  Calculate the expected infant's weight with areppim's Infant Growth Calculator.

 

Sources: see Wissenschaftliche Tabellen

 

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