Once your child outgrows his forward-facing car seat, it's time for a booster seat, and like infant car seats, booster car seats are required for children up to a certain age. A typical booster seat may or may not feature a back, but at the very least it will hold the seat belt in the correct place on your child's body. Car booster seat requirements vary from state to state.
According to Safe Kids USA, a child should use a booster seat in the car until he weighs between 36.3 and 45.4kg. The standard seat belt should fit correctly and provide adequate protection after that. Although some states, such as Kansas and New Jersey, require booster seats until children reach the 36.3kg. threshold, many states allow children to sit in a regular seat with a seat belt at a lower weight, such as California's 27.2kg. or Georgia's 18.1kg.
A child should stay in a car booster seat until he is at least 4 feet 9 inches tall, according to the National Highway Traffic Safety Administration. Vehicle seat belts do not typically fit properly or provide adequate protection for individuals under this height. State height requirements for booster seats vary. Although the standard height requirement to move a child from a booster seat to a regular seat belt is 4 feet 9 inches, or 57 inches, in most states, some states have much lower height requirements or no height requirements at all.
Car booster seats are intended to be used for children between the ages of 4 and 8, according to the National Highway Traffic Safety Administration. On top of the height and weight limits, many states also have car booster seat age requirements. Most states require you to keep a child in a booster seat until at least the age of 8, but some states, like Louisiana, have no age limit, and many states have lower age restrictions, like Texas, where a booster seat is required only until age 5.