Car booster seats are getting better and better, according to the Insurance Institute for Highway Safety (IIHS). They’ve just released their 2013 booster seat ratings, and of the 31 new models they tested, 19 earned the top rating of BEST BET.

Booster seats have been shown to lower the risk of serious injury among 4- to 8-year-old passengers by 45 percent. But the effectiveness of a booster depends on how well the lap and shoulder belts fit. Some models only work well in certain types of cars or depend on the size of the child — and the popularity and price of a booster don’t necessarily match its rating.

Why are booster seats necessary?

Booster seats are an important intermediate step between forward-facing harness seats and adult seat belts. Boosters make use of the vehicle’s backseat lap and shoulder belt, but they elevate your child so the belt is positioned properly. To avoid injury, the belt should fit across the strongest parts of your child’s body (the pelvis, shoulders, and chest), rather than the abdomen, face, or neck. Improperly fitted belts can put children at risk of injuries to the spine and internal organs.

Though state laws vary, children should use booster seats until they are big enough to fit properly in an adult seat belt, with their backs flat against the seat back and their knees fully bent over the front edge of the seat. For some children, this might not happen until the age of 12.

Types of booster seats

There are 3 types of booster seats: combination, high-back, and backless. Combination (or convertible) seats can be used with either a 5-point harness or the vehicle seat belt and are ideal if your child is in a transition stage between harness and booster seats. High-back seats offer head support and protection, while backless seats do not. Backless styles are compact and lightweight, but should only be used in vehicle seats with a built-in headrest. Some seats are dual-use, meaning they can be used as either a high-back booster or a backless booster.

Best booster seats: how the ratings work

Using 4 configurations that corresponded to different vehicle types, the IIHS tested how well 3-point lap and shoulder belts fit a child-sized dummy seated in the booster. (Crash tests were not part of the evaluation.) For a correct fit, the lap belt must lie flat over the upper thighs and the shoulder belt must be snug across the middle of the shoulder. Boosters were given ratings of BEST BET, GOOD BET, Check Fit, or Not Recommended. Dual-use models were tested separately in each mode and given 2 individual ratings.

To earn a BEST BET rating, the booster must provide a correct fit for an average-sized 4- to 8- year-old child in almost any vehicle. A total of 58 boosters — new models as well as carry-overs from previous years — met these criteria, including the Britax Parkway SG (high-back mode), Evenflo Amp (backless), and Graco Affix (high-back and backless modes).

A GOOD BET booster provides the correct fit in most vehicles. 5 boosters earned this rating: the Combi Kobuk Air Thru (high-back and backless), Evenflo Symphony 65 (high-back), Ferrari Beline SP (high-back), and Maxi-Cosi Rodi (high-back).

Check Fit means that the booster fits some children well in some vehicles. Before purchasing these seats, parents are urged to test the fit with their own child and vehicle. This year, 11 seats fell into this category, notably 3 new Britax models — the Frontier 90, Pinnacle 90, and Pioneer 70.

There are 2 seats in the Not Recommended category — the Safety 1st All-in-One and Safety 1st Alpha Omega Elite. Both are 3-in-1 styles that can be used as rear-facing and forward-facing seats with harness restraints and can also be converted to boosters. But, when used as booster seats, the lap and shoulder belts are unsafely positioned too high on the abdomen and too far out on the shoulder.

The IIHS began rating boosters in 2008. Since then, the number of BEST BUY seats available has increased greatly and the number of Not Recommended seats has fallen sharply. The IIHS attributes this to manufacturers focusing on meeting the ratings criteria. This means you can find BEST BET models that are convertible, dual-use, high-back, or backless in a range of different prices.

No matter what you decide, just remember the bottom line: it’s always important to check the latest ratings before you buy. Get the full IIHS list here.

Related links

Find out about child seat safety laws, inspections, and recalls
Get the facts on 5 common car seat myths

Safe and smart | Around the nation


about Ellen

Ellen has spent many years as a professional wordsmith, helping to shed light on such topics as world travel, cargo pants, and the porosity of bath tiles. As a freelance copywriter for Esurance, she brings her boundless curiosity to the world of insurance. Outside work, she can be found cheering on the San Francisco Giants, hiking in the Oakland hills, and (barely) resisting smuggling penguins home from Antarctica.