Baby seats are based on weight and/or height of your child, not age. It’s safest to keep your baby in their rear-facing car seat for as long as they fit the seat. Once they have grown out of the seat you can move them into a child car seat with a built in harness or shield.
Try to keep your child in their child car seat until they’ve grown out of it. If it’s a rear-facing car seat and the right size for your child it’s ok for their feet to be touching the back of the back seat.
When their eye line is above the back of the seat it’s time to move them to the next size of seat.
