Rear-facing infant car seats must be installed at the correct angle—upright enough to protect a baby during a crash, but reclined enough to prevent their head from falling forward potentially obstructing his airway. (See our infant car seat Ratings.)
The correct recline angle usually is between 30-45 degrees from upright, depending on the seat. The correct car seat recline angle is especially important for preemies, who may already have respiratory difficulties and are often checked in their child restraint for breathing and oxygenation before they even leave the hospital.
When it comes to getting the right angle, always refer to the child car seat manufacturer’s instructions, and install the seat at the recline angle designated by the instructions or the recline indicator on the seat itself. In many cases, this may mean using the recline-adjustment knob or other adjuster on the seat itself, or adding a rolled towel beneath the seat to reach that angle. Newer seats sometimes have “two-zone” recline indicators—one for younger babies and another that’s more upright as your baby grows—referring to the instructions and periodically checking your child’s seat is critically important.
See more child car seat installation tips.