For More Information, Please Call Us At call 603.524.3211

Health Information Library

Categories > Children’s Health > Children’s safety

Mayo Content Display

Your guide to child car seats
Choosing and using the safest seats

» Growing up

Age and size guidelines for car seats

No matter how appropriate a car seat’s size and features are for your child, an improperly installed car safety seat will not protect against fatal or serious injuries. Remember, place all children’s safety seats in the back seat. Never place a child in the front seat of a vehicle equipped with a passenger air bag.

Safety tips you can’t ignore

  • Carefully read the installation instructions that came with your child safety seat.
  • Follow the manufacturer’s instructions on how to use the seat’s restraints properly.
  • Read your vehicle’s instructions on proper seat belt and child safety seat use.
  • Never reuse a child safety seat that has been in a crash—even if it doesn’t look damaged.
  • Know that expensive car seats are not always the best car seats. The best car seat is the one that fits your child, regardless of price.
  • Never use a safety seat that is more than 10 years old (or older than suggested for use by the manufacturer).
  • Always check that harnesses and belts are in the proper position and fit snugly over your child.
  • Consider having your safety seat inspected for proper installation in your car by a certified child safety seat technician.
  • Be diligent about changing your child’s safety seat as he or she grows.
  • Never hold an infant or child in your lap when riding in a car.

Latch to attach

All new cars today must have the LATCH (Lower Anchors and Tethers for Children) system in place. LATCH is an attachment system built into vehicles, which matches features on newer child safety seats (hooks, buckles or other connectors) to ensure a secure fit.

Would your child’s car seat save his or her life? Are you sure? At least four out of five children riding in car seats are improperly restrained, according to the National Highway Safety Traffic Administration. And since more children are killed each year in car crashes than from any other type of injury, it’s crucial to have the right car safety seat—and to have it properly installed.

You also need to heed safety rules: Never place children under 12 in the front seat—especially if that front seat has an air bag. The inflated air bag’s force can cause death or serious brain injury to an infant or a child—even if he or she is riding in a safety seat.

When selecting a car seat, follow these guidelines:

  • Babies younger than 1 year and under 20 pounds should ride in infant-only seats, which must be rear-facing and semireclined at a 45-degree angle. Attach shoulder harnesses at or below your infant’s shoulders. Make sure the safety seat’s clip is level with your baby’s armpit, not his or her stomach or neck.
  • Convertible safety seats can be used rear-facing for infants and upright and forward-facing for toddlers who weigh from 20 to 40 pounds.

For forward-facing seats, place the shoulder strap at or above your child’s shoulders. Position the harness chest clip at armpit level.

  • Combination seats use an internal harness for toddlers and convert to belt-positioning boosters for children who weigh more than 40 pounds.
  • Once children reach 40 pounds and are less than 4'9" tall, they should be placed in booster seats, which allow their legs to bend normally.

Growing up

How do you know when your child has outgrown his or her booster seat? Children ages 8–12 and 4'9" tall can normally use a seat belt only. Follow these guidelines to determine if your child is ready for a seat belt:

  • The chest harness must fit snugly across your child’s chest, not touching the neck or throat.
  • The lap belt must lie snug over your child’s thighs, not the waist or stomach.
  • Your child’s knees must be able to bend over the edge of the vehicle’s seat when he or she sits back without slouching.

TypeChild’s age and weightBenefitsWarnings
Infant seat • birth–1 year
• 20 lbs. and under
• Can be removed from car and used as a baby carrier
• Best for newborns
• Infants outgrow them within a year
Convertible seatRear-facing:

   • birth–1 year
   • 40 lbs. and under


• 1–4 years
• 20–40 lbs.
• Can adapt to child’s size as he or she grows• May not fit newborns as well as infant seats
Combination seat• 1–4 years
• 20–40 lbs.
• Can adapt to child’s size as he or she grows• Can’t be used rear-facing
Booster seat• 4–8 years
• 40+ lbs.
• under 4'9"
• Adjusts vehicle’s existing lap and shoulder belts so they fit properly
• Keeps kids comfortable because legs can bend at a natural angle
• Never use just the lap belt alone
• Improper positioning of lap belt can cause abdominal injuries in a crash
Seat belt• 8–12 years and older
• 80+ lbs.
• over 4'9"
• Properly used seat belts save lives and decrease risk of injury• Kids who slouch or can’t sit still can move the belt out of proper position

© 2014 Dowden Health Media