(crown to rump measurements)

Gestational Age Length (inches) Weight (oz/lb) Length (cm) Mass (g)
8 weeks 0.63 0.04 oz 1.6 1
9 weeks .9 0.07 oz 2.3 2
10 weeks 1.22 0.14 oz 3.1 4
11 weeks 1.61 0.25 oz 4.1 7
12 weeks 2.13 0.49 oz 5.4 14
13 weeks 2.19 0.81 oz 7.4 23
14 weeks 3.42 1.52 oz 8.7 43
15 weeks 3.98 2.47 oz 10.1 70
16 weeks 4.57 3.53 oz 11.6 100
17 weeks 5.12 4.94 oz 13 140
18 weeks 5.59 6.70 oz 14.2 190
19 weeks 6.02 8.47 oz 15.3 240
20 weeks 6.46 10.58 oz 16.4 300
21 weeks 10.51 12.70 oz 26.7 360
22 weeks 10.94 15.17 oz 27.8 430
23 weeks 11.38 1.10 lb 28.9 501
24 weeks 11.81 1.32 lb 30 600
25 weeks 13.62 1.46 lb 34.6 660
26 weeks 14.02 1.68 lb 35.6 760
27 weeks 14.41 1.93 lb 36.6 875
28 weeks 14.80 2.22 lb 37.6 1005
29 weeks 15.2 2.54 lb 38.6 1153
30 weeks 15.71 2.91 lb 39.9 1319
31 weeks 16.18 3.31 lb 41.1 1502
32 weeks 16.19 3.75 lb 42.4 1702
33 weeks 17.20 4.23 lb 43.7 1918
34 weeks 17.72 4.73 lb 45 2146
35 weeks 18.19 5.25 lb 46.2 2383
36 weeks 18.66 5.78 lb 47.4 2622
37 weeks 19.13 6.30 lb 48.6 2859
38 weeks 19.61 6.80 lb 49.8 3083
39 weeks 19.96 7.25 lb 50.7 3288
40 weeks 20.16 7.63 lb 51.2 3462
41 weeks 20.35 7.93 lb 51.7 3597
42 weeks 20.28 8.12 lb 51.5 3685
43 weeks 20.20 8.19 lb 51.3 3717