A car seat is one of the few baby purchases where the wrong choice carries real risk, and one of the hardest to judge from a product photo. This guide covers what the US National Highway Traffic Safety Administration (NHTSA) says on its car seat page, so you know what to check on a listing. It covers US recommendations only. EU seats follow different standards that we did not read. Always follow your car seat maker's height and weight limits and your vehicle's manual.

This guide is based on the public source listed below, which we read in a browser on 17 October 2026 because automated readers are blocked. We have not tested any seat or store. Our Compare table sets out the stages.

What NHTSA recommends

Source: NHTSA, "Car Seats and Booster Seats" (the page shows no date). Last checked: 17 October 2026.

  • Birth to 12 months: always rear-facing. Infant-only seats can only be used rear-facing; convertible and all-in-one seats typically allow rear-facing for longer.
  • 1 to 3 years: keep rear-facing as long as possible, until the top height or weight limit of the seat, then move to a forward-facing seat with a harness and tether.
  • 4 to 7 years: stay in a forward-facing seat with a harness and tether until its top limit, then use a booster, still in the back seat.
  • 8 to 12 years: stay in a booster until the seat belt fits properly: the lap belt snug across the upper thighs, not the stomach, and the shoulder belt across the shoulder and chest, not the neck or face.
  • Back seat: keep children in the back seat at least through age 12.
  • Choose a seat by the child's age and size, make sure it fits in your vehicle, and use it every time.

Installation points

  • Install with either the lower anchors or the seat belt, never both.
  • Lower anchor weight limit: NHTSA gives the rule of thumb of 65 pounds minus the weight of the car seat. When a child outgrows the limit, stop using the lower anchors and reinstall with the vehicle seat belt.
  • Tether: NHTSA recommends always using a tether with a forward-facing seat, installed with the seat belt or lower anchors, as far as both makers allow. Most US rear-facing seats do not use a tether.
  • Test the seat in your car before you commit, because not all seats fit all vehicles. NHTSA also lists a Car Seat Finder tool and free inspection stations.

What to check on a listing

  1. The age, height and weight range of the seat, and which stages it covers (infant only, convertible, all-in-one, booster).
  2. The seat's weight (it sets the lower anchor limit) and its size against your back seat.
  3. Where the seat is made for. A US seat and a European seat follow different rules, so check what your country requires.
  4. Return policy. Car seats are often not returnable once used. Check recalls and register the seat with the maker.

What we could not confirm

  • EU seat standards, the page's ease-of-use ratings, how long a seat stays safe to use and any particular seat.

Source: NHTSA, car seats and booster seats.