As we wrote in our guides to infant and convertible car seats, the stringent rules surrounding car seat use are merited. NHTSA estimates (PDF) that the lives of nearly 9,000 children under the age of 5 were saved by the use of car seats or safety belts between 1975 and 2008. Once you’ve chosen a seat, you can maximize your kid’s safety by being sure to:
Cons: Booster function is outgrown in height very quickly after the harness is outgrown by height, does not convert to backless, harness must be fully removed when switching to booster mode, lower weight limit than other combination seats, must remember to move crotch buckle out when child reaches 40 lbs, and narrow set harness straps may dig into child's neck.
Why is this one of the safest infant car seats? Well, this Britax car seat has a very unique feature. As a matter of fact, this feature is available in just this car seat. The Britax SafeCell Impact Protection system keeps babies safe. This includes a steel frame and an energy-absorbing base. In the instance of a car crash, your baby is protected by this car seat!
Our comments: Budget-friendly seats for extended rear-facing! 2 year age minimum age for forward-facing use. Both Sonus & Stratos fit a wide range of kids – from small babies to older kids ready for a booster. Lightweight and great for traveling. LATCH weight limit is higher than most other seats on the market. These seats lack a lockoff for seatbelt installations so you must read your vehicle owner’s manual to determine how your seatbelts lock in order to properly install this carseat with seatbelt. Check out our Comparison of Convertible Seats Under $100.
Graco’s MyRide 65 is one of our favorite convertible car seats, due to its enviable combination of great price (sub-$125) and extended use. With a weight range of 5-65 pounds, this seat will get you from the hospital through the elementary years – until your child is ready to transition to a backed booster. Graco’s excellent safety features clinch the deal: it exceed U.S. safety standards with EPS energy-absorbing foam, high ratings for side-impact protection, an adjustable 5-point harness, LATCH compatibility, and other keep-your-kiddo-safe features.

The upgrade Chicco KidFit Zip and Chicco KidFit Zip Air are the same seat as our runner-up pick but with zip-off covers designed for easy cleaning. The Zip Air also comes with extra padding and a leg rest, which testers didn’t find that useful, and both the Zip and Zip Air include a console attachment with a lid, which our kid testers loved to use as a private toy stash (the console is also available for purchase and fits into the regular Chicco KidFit cupholder, though a representative of the company told us that the console is not intended for use with seats other than the Zip).
Baby Trend makes a great line of baby products that tend to be a bit less expensive than the major brands, but we also find that their products are not quite up to par with craftsmanship. This Baby Trend FlexLoc is no exception. All the major features are here: a nice 5 to 30 pound weight range, adjustable leveling base, no-rethread shoulder strap height adjustment, EPS energy absorbing side impact foam, a reasonably large canopy, and the ability to snap easily into several Baby Trend strollers like the Expedition Jogger and the Snap N Go EX. There are also some other great features. We really liked the soft multi-grip handle that allows you to carry it with your hand at a 45-degree angle or aligned with your body. This made it much easier for longer hauls, allowing us to switch hand positions to relieve some hand and arm pain! Not that it's particularly heavy: the car seat itself is only about 9 pounds, and the base is 6 pounds. It also has the typical removable infant insert for the little ones around 5-15 pounds. So with all these great features, why is it toward the bottom of our top rated infant car seat list? Well, we had a few gripes. First, the handle was a bit finicky to use, and we had repeated troubles getting it to go back easily. The mechanism isn't very easy to use, requiring you to push two finicky buttons (one on each side) to adjust. We looked around at other reviews and turns out this is a pretty common problem. Second, Baby Trend uses a somewhat unique crotch buckle design that is a little harder to buckle relative to others on this list (making us think it was a little too hard to make this Baby Trend secure). Finally, we also do not like the positioning of the lever to release the seat from the base, which is positioned at the front of the seat near the baby's feet. The problem is when rear-facing that side of the seat is jammed up against the seat of the car, making it difficult to use. So this unit has a lot of great features, but also some more design decisions that had us scratching our heads. Low cost, but also a bit lower on the ease of use! 

Our comments: Both Nautilus models offer a no-rethread harness. Both are generally easy to install and use correctly although the new Nautilus SnugLock model has a nifty tensioning and locking feature that makes it super easy to achieve a secure installation. Use seatbelt plus tether to install if child weighs more than 45 lbs. Since the original Nautilus models lack a lockoff for seatbelt installations you must read your vehicle owner’s manual to determine how your seatbelts lock in order to properly install that model with seatbelt. The original Nautilus models and the Nautilus SnugLock DLX have a Best Bet rating from the IIHS when used in highback mode.
Though this seat meets or exceeds all safety standards in the US, it is made in China, so there can be some quality control issues. Some parents noted that food can get caught in the harness tension latch, which could hinder proper tightening. Always check the latch and clean any loose debris before using it. There is no backless booster mode, which some parents didn’t like.
The Chicco Fit2 infant car seat is a step above the top-rated KeyFit in its dual-mode design and added safety features. The unique 2-stage adjustable base allows for a better fit for toddlers who are rear-facing. For those who are worried about lack of legroom for toddlers, this could be a great option. It comes in 3 colors and is designed for babies 4 – 35 pounds.
Graco adds another to our list with the Size4Me, an adaptable and well-priced entry to the convertible car seat market. It is incredibly safe, thanks to demanding side-impact testing, energy-absorbing foam, and a five-point harness that earns the seat high safety ratings. We also love that the Size4Me has a low, low weight minimum (just 4 pounds), so even if you’re expecting a premie (or multiples!), this seat will still take you from hospital to elementary school.
Comments: Fits preemies and small newborns well. Easy to install in a variety of vehicles with either lower LATCH anchors or with seatbelt. The carrier is almost the same as the B-Safe 35 Elite; however, the Endeavours has the anti-rebound bar on the base and the capability to be installed without the base using the European belt routing. See our full review of the Britax Endeavours here.
Our comments: One of the easiest convertibles to install correctly with either LATCH or seatbelt. Installing with SuperCinch is so quick and easy that it’s downright revolutionary. Use seatbelt plus tether to install if child weighs more than 40 lbs. Fits newborns (even small newborns) very well. Doesn’t take up a lot of space when rear-facing so it’s a good option for smaller vehicles. Generous rear-facing height and weight limits. Almost all kids will be able to rear-face in the NextFit until they reach 40 lbs. Well-padded and very comfortable. We love the extra convenience of the zip-off cover found only on Zip models. See full review of the Chicco NextFit here.
The Graco Milestone All-In-One is a promising car seat that, while relatively new on the market, parents are pleased with. This seat comes in a rear-facing mode from 5-40 pounds, a forward facing mode with a harness from 20-65 pounds, and a high-back, belt-positioning booster for 30-100 pounds. It comes in 2 colors - Ayla (pink/white) and Gotham (black w/ white trim).
Our comments: We recommend only for kids over 4 years old who weigh at least 40 lbs. and are mature enough to sit properly in a booster. It’s budget-friendly, LATCHable and tends to fit kids of different ages and sizes well. We only wish it was taller! The Affix has a Best Bet rating from the IIHS in both highback or backless mode. See our review of the Graco Affix here.