When your baby reaches an infant seat’s height and weight limits, which may be as soon as 6 to 9 months old, you’ll need to switch to a convertible car seat in order to keep her rear-facing. Use a convertible car seat rear-facing until your baby is at least 1 year old and weighs 22 pounds or more. Some convertible seats can be used in the rear-facing position for children who weigh up to 30 to 35 pounds. And research shows that babies are safest in a rear-facing orientation so it’s best to keep them that way for as long as you can.

When your baby reaches a convertible seat’s height and weight limits in the rear-facing mode, switch the seat around, and use it facing forward until your toddler reaches the height and weight limits for the forward-facing seat. Weight limits for most are generally up to 40 pounds, though more and more convertible models have weight limits up to 65 pounds or more.

See our car seats buying guide, and see our latest convertible car seat Ratings of 16 models, just posted.