One of the most common questions I get from parents of three or more is, "How do I fit three car seats across?"

I know you want me to tell you, "Buy this car seat and you'll fit three across no problem!" I wish it were that simple, but the truth is that three-across setups are a puzzle. Your vehicle, your children's ages and sizes, whether they're rear-facing or forward-facing, and the combination of seats you're using all play a role.

One thing I can say with confidence is that starting with slimmer car seats gives you a much better chance of making three across work.

In fact, one of my favorite questions to ask parents is: Do you actually need a new car, or do you just need new car seats?

Sometimes the answer really is a larger vehicle. But I've also seen plenty of families make their current vehicle work simply by switching to narrower car seats. Before you start shopping for a new SUV or minivan, it's worth seeing whether a different combination of car seats solves the problem. I have a list here of cars that are three across friendly in many scenarios.

If you're trying to fit three car seats across, these are the slim models I'd start with.

Why Choose a Slim Car Seat?

Not every family needs a slim car seat, and that's important to remember. If you have plenty of room in your vehicle, a wider seat may fit your needs just fine.

But if you're trying to fit three car seats across, create a little more elbow room between siblings, or simply maximize the space in your second row, a slim car seat can make a big difference.

The good news is that manufacturers have caught on. There are far more narrow car seats on the market today than there were just a few years ago, and they're designed to be just as safe and comfortable as their wider counterparts. Every car seat sold in the United States has to meet the same federal safety standards, regardless of its width.

Another thing to consider is longevity. Most car seats last somewhere between seven and ten years. Even if you don't need a three-across setup today, choosing a slimmer seat now could give you more flexibility if your family grows before it's time to replace it.

Best Slim Infant Car Seats

• Clek Liing
• Chicco KeyFit Max

In situations like these, you could also consider a baseless infant seat, which has quickly become our favorite! Because these seats don't require a separate base, they can sometimes make a tight three-across configuration a little easier. Plus, they are incredibly convenient!

Our favorites include:

• Joie Mint Latch
• Graco GoMax
• Nuna Pipa URBN

Clek Liing

Aside from the price, the Clek Liing is one of my favorite infant seats for families trying to fit three across. It's compact, packed with premium safety features, and its narrow footprint makes it a great option.

Why we like it:

• Advanced safety features, including a load leg, rigid LATCH, and baseless European belt path routing
• 9-year expiration, making it a great investment for growing families
• Compact design that's especially impressive for a seat with a load leg
• Three-across friendly

Chicco KeyFit Max

The Chicco KeyFit Max is one of the easiest infant seats to install and does an excellent job fitting even the smallest babies.

Why we like it:

• Super straightforward installation
• Excellent fit for newborns and preemies (not all infant seats do!)
• Very compact and narrow
• Three-across friendly

Joie Mint Latch (Baseless Infant Seat)

If you're really tight on space, the Joie Mint Latch is worth a look. Since it doesn't require a traditional base, it can be an excellent solution for families trying to make three across work.

Why we like it:

• Integrated rigid lower anchor connectors for simple installation
• Ultra-compact design that's great for travel, rideshares, and tight spaces
• Optional accessory base lets you use it baseless in one vehicle and with a base in another
• Three-across friendly

Best Slim Convertible Car Seats

• Graco SlimFit3 LX - Our most recommended for 3 across setups
• Britax Poplar - Install couldn't be easier because of the ClickTight technology
• Evenflo Revolve360 Slim - A slim rotating car seat option

Slim or not, these are three of our most recommended convertible car seats. You can't go wrong with any of these seats!

Graco SlimFit3 LX

If I had to pick an MVP for three-across setups, this would be it.

Why we like it:

• Built-in lock-off for easier forward-facing installation
• Rapid Remove cover for easy cleaning
• Only 16.7 inches wide
• One of the best options for three across

Evenflo Revolve360 Slim

If you love the convenience of a rotating seat but still need to maximize space, the Revolve360 Slim is hard to beat.

Why we like it:

• Rotates 360 degrees in both rear- and forward-facing modes
• True one-time installation
• Seat belt tensioner makes installation easier
• Narrow 16.7-inch design
• Three-across friendly

Britax Poplar

The Britax Poplar combines an incredibly easy installation with one of the narrowest footprints available.

Why we like it:

• ClickTight technology with built-in lock-off and tensioner
• Machine-washable, dryer-safe cover
• Extremely compact
• Just 17 inches wide
• Three-across friendly

Best Slim Booster Seats

• Peg Perego Viaggio Flex 120
• Graco TurboBooster 2.0 Highback Booster
• Chicco MyFit Harness + Booster
• Evenflo GoTime LX High Back Booster

Peg Perego Viaggio Flex 120

This is one of my favorite boosters for tight three-across setups because the narrow base improves access to the buckle.

Why we like it:

• Excellent buckle access when installed next to another car seat
• Rigid LATCH keeps the booster secured when unoccupied
• Starts at just 17 inches wide and expands as your child grows
• Three-across friendly

Graco TurboBooster 2.0

If you're looking for a narrow, budget-friendly booster, this is a great place to start.

Why we like it:

• Hide-away cup holders
• Converts to a backless booster
• Narrow 16.7-inch design (this version, not the LX)
• Three-across friendly

Chicco MyFit

The Chicco MyFit is technically a combination seat, but it's one I recommend often for families trying to keep kids harnessed longer in a three-across setup.

Why we like it:

• Highest harness height on the market (54")
• Built-in lock-off for easier installation
• Narrow 17.5-inch design
• Keeps kids harnessed longer, which can make three-across setups easier than switching to a booster
• Three-across friendly

The Best Slim Car Seat Depends on Your Vehicle

There isn't one slim car seat that's best for every family.

The right choice depends on:

• Your vehicle
• Your children's ages and sizes
• Whether they're rear-facing or forward-facing
• Which car seats need to fit next to each other

That's why I always recommend looking at the entire puzzle instead of focusing on just one seat.

We've also put together a guide to the best vehicles for fitting three car seats across, which can help you decide whether you need a different seating arrangement, slimmer car seats, or a different vehicle altogether.

Frequently Asked Questions About Slim Car Seats

What is the slimmest car seat?

There isn't one universal answer because it depends on the type of seat you're shopping for. Some of our favorite slim options include the Clek Liing for infants, the Graco SlimFit3 LX and Britax Poplar for convertible seats, and the Peg Perego Viaggio Flex 120 for booster-age kids.

Are slim car seats as safe as regular car seats?

Yes. Every car seat sold in the United States must meet the same federal safety standards, regardless of whether it's considered slim or wide. A narrower seat does not mean it's less safe.

Can you fit three car seats across in an SUV?

Many SUVs can accommodate three car seats across, but it depends on the vehicle and the specific combination of car seats you're using. In many cases, switching to slimmer car seats is enough to make three across possible without buying a larger vehicle.

Do I need a new car for three kids?

Not necessarily. One of the biggest misconceptions I hear is that a third child automatically means it's time for a new vehicle. Sometimes that's true, but many families can successfully fit three across simply by choosing different car seats.

What's the best car seat for three across?

There isn't a single best option. The ideal car seat depends on your vehicle, your children's ages and sizes, and how the seats need to fit together. Starting with a slim car seat gives you more flexibility and increases your chances of finding a successful three-across configuration.

Should I buy a slim car seat if I'm planning to have more children?

It can be a smart investment. Since most car seats last 7 to 10 years, choosing a slimmer model now may give you more options if your family grows before the seat expires. It doesn't guarantee you'll fit three across, but it can make that transition much easier.'=