How to Fit Car Seats Three Across
Experts also share top tips for safely securing three small children in one rear seat
When you shop through retailer links on our site, we may earn affiliate commissions. 100% of the fees we collect are used to support our nonprofit mission. Learn more.
Having a third kid levels up both the joy and the logistical considerations. This is never more apparent than the first time you test out whether three car seats across the back seat will be doable, reachable, and safe in your current vehicle.
While this is when some parents realize it’s time for a trip to the car dealership, for many vehicles, accommodating three car seats across is possible with a few tips and the right seats.
“One of the most common questions we hear from consumers is ‘Which cars and car seats will make it easy for me to secure three child car seats across the back seat?’” says Emily A. Thomas, PhD, Consumer Reports’ associate director of auto safety and mom of two young kids. Laws in many states now require children to ride in booster seats until at least age 8, and safety experts recommend that children ride in a booster seat until age 10. This means that anyone with more than two children is very likely to encounter the challenge of fitting three car seats into the rear of their vehicle. Bulky all-in-one car seats and revolving car seats that take up extra space can add to the challenge.
But before you decide on a new car seat—or a new car—check out these tips from Consumer Reports’ child passenger safety experts for safely securing three kids across the back seat.
Choose Narrower Car Seats
Child car seat dimensions vary greatly, as do accessories that can change the overall footprint of the seat, such as cup holders. You can look for accessibility and versatility in car seat accessories and extras, such as collapsible cup holders.
CR’s car seat safety technicians recommend looking for a car seat that’s no wider than 18 inches if installing car seats three-across is your goal. “We measure the overall width (at the widest part) of all the seats we test,” says Michael Bloch, who helps lead child seat testing at Consumer Reports.
But while some car seats are marketed as “slim,” bear in mind that “‘slim’ is a marketing term, not a standard. While they often lean toward the narrower side, some ‘slim’ car seats we’ve tested are no narrower than the regular version of a seat, while some of the narrowest seats lack ‘slim’ in their name,” says Bloch.
To help in your search for a narrower car seat, CR’s ratings include the option to sort them by overall width. You can also filter CR’s car seat ratings by “good small car fit,” which can help identify the seats that may work best in cars with lower clearance or smaller back seats.
Photo: John Powers/Consumer Reports Photo: John Powers/Consumer Reports
The Best Slim or Narrow Car Seats From CR’s Tests
The following seats are highly rated (very good or excellent overall) from each category and also have some of the skinniest dimensions.
Narrow Infant Car Seats
Narrow Convertible and All-in-One Car Seats
Narrow Booster Seats
Alternate Forward- and Rear-Facing Seats
Photo: John Powers/Consumer Reports Photo: John Powers/Consumer Reports
Alternating forward- and rear-facing seats can help you save space with a three-across installation if it’s safe for your children’s specific ages (see our age-by-age guide to when children can ride rear-facing vs. forward-facing). Think about which seats should be backward- and forward-facing, and whether you can alternate them or use certain combinations to help them fit best.
Consider traffic flow inside the car, too. Do you have a toddler who can climb in on their own but needs some room to do so? “Prioritize the arrangement that makes the most sense for your family. For example, will you need to get a wiggly toddler in the car first before clicking in your baby’s infant car seat? Or will an older child be able to sit in the middle and buckle their own booster safely, so your younger kids can be on the outside spots?” says Jessica D’Argenio Waller, a baby and health reporter at Consumer Reports. “The arrangement that’s best for your family will be the one that makes getting everyone in and out of the car easiest.”
D’Argenio Waller recommends doing some mental (and physical) work before actually installing. “I’d recommend that parents really embrace a puzzle mindset and try a few different combinations to find the best installation for your car’s back seat and your family’s needs,” she says. “That might look like lining up all three on your driveway first in different orientations to see how the seats fit together and to think about how you’ll buckle in your children. That’s much easier than wrestling with a bulky car seat in a tight back seat row.”
Watch for Child Car Seat Interactions
Sometimes even the narrowest child car seats may not work if their shapes interfere with one another. You may have two narrow seats, but if their armrests meet at exactly the same point, that may make it impossible for them to fit side by side. It takes a bit of trial and error, but try to position seats so that they don’t overlap at their widest points.
Some safety issues should also be considered, like “wedging car seats into place so they’re bumping up against each other and assuming they’ll stay that way. While it’s okay for car seats to touch when placed next to each other, it’s not okay for them to rely on each other for stability or a secure fit,” D’Argenio Waller says.
Learn About LATCH, but Know Its Limitations, Too
LATCH, which stands for Lower Anchors and Tethers for Children, is a convenient system of vehicle-integrated anchors that you can clip car seats into—and it can be helpful for some three-across car seat installations. Since 2002, every vehicle sold in the U.S. has been required to come equipped with LATCH anchors in the second-row outboard seats (the seats closest to the doors).
But LATCH anchors aren’t mandated for the rear center seat, so not all vehicles have them there. “Most cars still lack dedicated lower anchors in the rear center seats, and sometimes center-seat lower anchors overlap into the outboard seats or even borrow an anchor from the outboard seat,” Thomas says. “That’s because vehicles are engineered with the assumption that there would be one or two car seats.” This can make a three-across car seat installation more complicated, so it’s important to know where the LATCH anchors are in your vehicle. Check your owner’s manual for information about LATCH anchor positions and spacing (standard LATCH lower anchor spacing is 11 inches), and whether LATCH anchor borrowing is allowed and safe in your car. And check your car seat manual to find out if LATCH borrowing is permitted for your car seat, and the allowed spacing between LATCH anchors.
1 / 2 : Not all vehicles have dedicated LATCH anchors for the center rear seat.
Photo: John Powers/Consumer Reports
You might consider installing car seats three-across using LATCH anchors and seat belts alternately to save space. But know the rules for doing this safely. “Yes, you can use LATCH on one child seat, and a seat belt on another, but you can’t ‘share’ LATCH anchors between seats [having two seats attached to the same anchor],” Bloch says.
“It’s not safe to double up on the lower anchors—one LATCH connector per anchor!” D’Argenio Waller says. “Because LATCH is so easy to use, I think parents sometimes hesitate to use a seat belt installation, but it’s an equally good option in many cases, and can help you get a successful and safe install in the middle seat when using three-across.”
The other issue to watch out for is making sure you don’t exceed the vehicle’s lower anchor limit, which caps at 65 pounds for the combined weight of the child car seat and the child. This means for heavier car seats (like some all-in-one or rotating car seats), your ability to use a LATCH installation will be limited—the average LATCH weight limit for convertible and all-in-one seats in CR’s ratings is 41 pounds forward-facing and 36 pounds rear-facing. You’ll also want to make sure that you’re not using both LATCH and the seat belt on the same child car seat. Car seats are tested to be used with only one installation method at a time (either LATCH or seat belt), and doubling up could be dangerous.
Don’t Default to a Booster
Any parent who has had a hand stuck in a narrow opening between car seats while they dig for a seat belt knows that sometimes harnesses are easier to use than seat belts when it comes to booster seats.
Photo: John Powers/Consumer Reports Photo: John Powers/Consumer Reports
“Even if your child is old enough to safely ride in a booster seat, the need for buckling the belt on every trip with a booster in the narrow space left between the other seats may prove especially difficult,” Thomas says. “Consider keeping even a booster-age child in a harnessed seat that will accommodate their weight and height. Even though the initial installation may prove a chore, the access to the harness afterward will be from the front of the seat, which will probably be easier for all.”
Choose the Most Helpful Car
While new-car shopping isn’t always your first step toward fitting three across, some parents may find that welcoming a third child is the right time to consider a larger or more accessible vehicle.
“If you’re looking to buy a car to better suit your three-across needs and you don’t want a model with three rows of seats, refer to our list of the best cars for three-across car seat installations, as well as some features to keep in mind for whatever car you may be considering,” Thomas says.
Photo: John Powers/Consumer Reports Photo: John Powers/Consumer Reports
Your highest priority for safely securing three seats should be a vehicle with a flat rear seat. “Deep contours for the outboard seats or raised center humps can limit the flexibility to move car seats side to side,” she says.
Parents shopping for cars to install three-across should remember they can go to a dealership to test how their car seats will fit before buying. Ask lots of questions and double-check the setup yourself, or read the online manual for the specific car model you’re interested in before you go.
Ask an Expert
Bloch recommends making a child passenger safety technician appointment to avoid guesswork, especially before making any expensive purchases. “They have the training, knowledge, and resources to help you achieve safe installations and guide you on the best compromises for your situation,” he says. You can also educate yourself on the most common mistakes parents make with car seats.
“Car seats can be challenging enough to install securely and use correctly, even when you have just one,” he says. Be ready for some trial and error in making three-across work and be willing to return a new seat if you can’t.”
Remember: The configuring, reconfiguring, and car-seat-moving phase is annoying, but it will pass. In the end, prioritizing a configuration that fits your family’s lifestyle will ensure that kids travel safely and securely for every ride.
