In a crash at just 30 miles per hour (48.3 kilometers per hour), an unrestrained passenger is thrown forward with a force 30 to 60 times their body weight. Learn more about crash dynamics. Seatbelts are designed to hold you into the car and spread the destructive force of the impact over the more resilient parts of your body, increasing your chances of avoiding death or serious injury in a crash by up to 50 percent. Learn more about seatbelts.

There are three basic types of child car seats, each designed for different ages (and sizes) of children:

  • Rear-facing infant seats and convertible seats
  • Forward-facing car seats
  • Booster seats and backless boosters

Learn more about types of car seats. Rear-facing infant seats are generally suitable for babies up to 22 pounds (about 10 kilograms), roughly from birth to 12 months. Learn more about rear-facing car seats. According to the National Highway Traffic Safety Administration (NHTSA), all children ages 12 and under should ride in the back seat. Learn more about car seat safety. Rear-facing car seats provide greater protection for the baby's head, neck and spine than forward-facing seats. Learn more about rear-facing car seats. Types of car seat harness styles:

  • The three-point harness has straps that cross over the shoulders and fasten to a buckle near the bottom of the seat.
  • The five-point harness has five straps: two at the shoulders, two at the hips and one at the crotch.
  • The overhead shield features a padded shield that swings down around the child, similar to the restraints often found on fairground rides.
  • A t-shield comprises a padded t-shaped or triangular shield attached to shoulder straps. Rather than swinging over the child, this shield is attached to the front of the unit.

Learn more about car seat harness styles. For children older than 1 year and heavier than around 20 lbs (9.1 kg), a forward-facing seat becomes suitable. Learn more about forward-facing car seats. According to the NHTSA, placing a child in the back seat instead of the front seat reduces the risk of death by 27 percent, whether the car has a passenger-side airbag or not. Learn more about car seat safety. When a child is too big for a harnessed car seat, it's time to use a booster seat. A child is to be considered "too big" if he exceeds the manufacturer's weight limit or the top of his head is higher than the top of the seat. Usually a child will need a booster seat between the ages of four or six. Learn more about booster seats. A seatbelt is designed to sit across the pelvis and ribcage, spreading the force of an impact over the strongest parts of our skeleton. A booster seat works by raising the child so that the adult seatbelt fits across these areas. Learn more about booster seats. Usually by the age of six, or when a child can sit up straight on his own without slumping or slouching, he can graduate from a full booster seat to a backless booster seat. A backless booster seat is simply a standard booster seat without the backrest. Learn more about booster seats. A child ready to use an adult seat belt without the aid of a booster seat will be around 4 feet, 9 inches (about 1 1/2 meters) tall and roughly eight years old. Please keep in mind that, because children do vary in size by age, some children could still need a booster seat at the age of 10 or 11. Learn more about booster seats. A child is not ready to use a regular seat belt until:

  • He is tall enough so that his legs bend at the knees against the edge of the seat.
  • He is mature enough to remain seated with his back flat on the seat, not slouching.
  • The lap belt sits high on the thighs or low on the hips, not on the stomach.
  • The shoulder belt crosses the shoulder and chest, avoiding the arms and the neck.

Learn more about seat belt recommendations. Whether you're purchasing something new or second-hand, pay attention to recall notices. For more information regarding child car seat recalls, check out the U.S. Consumer Product Safety Commission Web site or the NHTSA Web site. Learn more about recall notices. LATCH stands for "Lower Anchors and Tethers for Children" and eliminates the need to use seat belts to secure the child car seat to the vehicle. However, your vehicle must be fitted with the anchor system. In 2002, most new vehicles began to be manufactured with the LATCH system installed. Learn more about the LATCH system. LATCH is not necessarily safer than using seat belts to secure a car seat, though it may make it easier to achieve a safe installation. Your child car seat retailer will be able to advise you on suitability for your vehicle. Learn more about the LATCH system. Here's what to look for when buying an infant car seat:

  • Use a rear-facing seat, rated for up to 20 pounds (9.07 kilograms). You will be able to find models that go to 22, 30 or 35 pounds (9.8, 13.6 or 15.9 kilograms), if necessary.
  • A 5-point harness is preferred.
  • A front adjuster to tighten the harness makes it easier to use.
  • Newborn babies and infants should have a maximum recline of 45 degrees. Some car seats have built in angle indicators and adjusters to help get the correct recline.
  • Most models with a handle will require that the handle be lowered when traveling.
  • A rear-facing tether, impact foam and rebound bar may improve safety. "
  • Dedicated infant seats may fit your child better than convertible models.
  • Some models may include a complete base system and stroller, while others may just have a convenient base. Select the system that is most suitable for you.

Learn more about infant car seats. When looking for a convertible car seat, you'll want to keep the following in mind:

  • A rear-facing seat is safer. Select a model with a 30 or 35 pound (13.6 or 15.9 kilogram) rear-facing weight limit and keep your child rear-facing as long as possible.
  • Your seat should be converted to front facing when the top of your child's head reaches the top of the seat, or when the child reaches the 30 or 35 pound (13.6 or 15.9 kilogram) rear-facing limit.
  • Try to find a model with a 5-point harness and a front harness adjuster.
  • Some models feature tethers that can be used rear-facing and have impact foam for added safety. Some models may also have built-in locking clips.

Learn more about convertible car seats.

When buying a booster seat, consider this:

  • You should use a booster seat after your child reaches 40 pounds (18.1 kilograms).Use it with a lap and shoulder belt.
  • Use the booster seat until the manufacturer's weight limit is met or until your child can wear a seatbelt properly.
  • Use a high backed model if your vehicle has low seat backs with no head rests. A backless model is fine if your vehicle has headrests.
  • Many booster seats have adjustable head supports and extra padding for comfort. Learn more about booster seats.

Here are some helpful links: