Generally speaking, you should switch from an infant car seat to a rear-facing convertible or all-in-one seat once your baby reaches the maximum weight allowed by the infant car seat manufacturer. Most infant car seats allow children up to 30 pounds in weight, but this can vary by model. Refer to your car seat manuals for specific information. Additionally, you should check the expiration date of your car seat. Car seats have a limited lifespan and need to be replaced accordingly. Finally, it’s important to remember that your child should remain rear-facing until they exceed their car seat's weight limit or height restriction.