I have a big baby. 6 months 18 days is 30 in and 22 lbs appx. I've read for the convertible car seats I'm looking at that they can be forward facing at 22 lbs 27 in. I know that it is recommended to rear face to 2 yr old. His whole fathers side is tall like 6 ft and over. So do I go by age or weight/height? Everyone thinks he is at least 1 and asking me why I carry him around lol.