Is your child big enough for a booster seat? After children are too big to sit in a rear-facing seat, NHTSA recommends keeping kids in a forward-facing seat with a five-point harness as long as allowed by the seat's manufacturer. After that, but generally not until at least age 4, children are ready for a belt-positioning booster, always in the back seat. While some manufacturers list minimum weights for belt-positioning boosters as low as 30 pounds, experts agree that using a five-point harness for as long as possible is the safest bet. A combination seat that converts from a forward-facing seat with a harness to a belt-positioning booster can give parents the best of both worlds.
Do you travel frequently, or will your child often be carpooling with friends? Some combination and high-back booster seats are heavy and bulky -- not exactly ideal for kids who will be switching vehicles. Choose a lightweight, easy-to-tote seat for traveling or carpooling. Backless booster seats are particularly worth a look for ease of use and portability.
Is space tight in your vehicle? You may have a smaller vehicle with a cramped back seat, or perhaps you need to fit three car seats in one row. Look for a seat with a narrow width to maximize space. Just test it first to make sure it doesn't put the squeeze on your child.
Do you frequently take long trips? You may be past the days of driving aimlessly in hopes of getting your child to nap, but boosters should still be comfortable enough to accommodate a short snooze. At a minimum, look for an adequately padded seat and adjustable armrests. If your child is a good car sleeper, consider a high-back booster with deep head wings to minimize head slump. Cup holders are also a nice bonus, but ensure they're big enough to be functional -- they should at least accommodate a standard water bottle.
Are you picky about how the seat looks? Many boosters come in an array of fabric choices, from neutral shades to vibrant colors. However, to find the widest selection, you may need to shop online. Major retailers often only stock a few options for even the most popular booster seats. Kids who may otherwise balk at booster seats due to their age may be more cooperative if they pick out a fabric or style they like.
Can you rely on your child to keep the seat clean? While spit-up and diaper blowouts may be a thing of the past, your booster seat will still need to stand up to grime, spilled drinks and snacks, and even occasional car sickness. Look for a seat cover that's easily removable and machine washable -- most are, but not all.
Does your vehicle have contoured seats or low seat backs? A booster seat needs to fit well in your vehicle and grip the seat surface properly. If you have low seat backs or no headrests, a high-back booster will better protect your child in a crash.
Do you want to use the seat for more than one child? Like all car seats, booster seats expire. Unlike infant or toddler seats, however, you could be using a booster with a single child for four or more years. This makes it especially crucial to check the seat's expiration date if you hope to use it again. Some models expire six years after they're manufactured, but a few have longer shelf lives -- check before you buy.