Pediatric car seat rules

1. Rear Facing
   1. >=2 years, OR
   2. Maximum weight for car seat (~40-65lbs)
2. Forward facing
   1. >= 4 years, OR
   2. Maximum weight for car seat (~65-80lbs)
3. Booster & rear seat
   1. >=4'9" height, OR
   2. 8-12 years
4. Front seat
   1. >=13 years

Source

AAP 2011