In Utah, children up to age 8 (through age 7) must be in an appropriate child safety seat or booster seat when traveling in a passenger vehicle. There is an exception to the law that states that children younger than eight are not required to be in a booster seat if they are at least 57 inches tall (4'9"). At that point, they should use the vehicle's lap and shoulder belt without a booster.
We HIGHLY recommend you checking out this website. It has a very powerful short video that will hopefully make you look at your own child's safety seat. It also has so many resources including, booster basics, list of fitting stations, and a question and answer section that answers so many questions.
It takes just a few minutes to check out this website and all of our doctors at Willow Creek Pediatrics think it is a great reminder to buckle up with a booster, and the correct way.
**Info from the boosttil8.org