To find out how many weeks are in 8.5 months, you can use a simple manual calculation method. First, note that an average month consists of about 4.3 weeks. Multiply this by the number of months, which is 8.5 in this case. So, 4.3 weeks x 8.5 months equals 36.55 weeks. This means there are approximately 36.55 weeks in 8.5 months.