How long will my baby use an infant car seat?

Most infant carriers are rated rear-facing for babies up to roughly 22 to 35 pounds, and reviewers note many babies outgrow them by height before weight. The Chicco KeyFit in this roundup tops out at 22 lbs, while several Graco SnugRide models reach 30 to 35 lbs, so taller or heavier babies may get more months out of the higher-limit seats.