Question: 11 mm baby how many weeks?
Answer: For example, a gestational sac measuring 11 mm would be approximately 5 weeks and 4 days gestational age. (4 weeks plus 11 days = 5 weeks and 4 days). Crown Rump Length: Gestational age = 6 weeks plus (CRL x days). This relies on the growth of the normal fetus of 1 mm per day after the 6th week of gestation.