The Crown-rump Length

Weeks	CRL (cm)
6.0	.45
6.5	.65
7.0	.92
7.5	1.3
8.0	1.5
8.5	1.9
9.0	2.2
9.5	2.7
10.0	3.1
10.5	3.6
11.0	4.1
11.5	4.7
12.0	5.2
12.5	6.0
13.0	6.5
13.5	7.4
14.0	7.9