2023 Graco SlimFit 3-in-1 Review: Narrow and Affordable

Original Graco SlimFit All-in-One Car Seat Review

We have a separate review here for the all-new ultra slim SlimFit3 LX 3-in-1 model, which launched in 2021. The newest SlimFit3 LX model is even slimmer than the original model since it was specifically designed for 3-across situations, but it’s also not as affordable as the “OG” SlimFit model.

A common issue that parents and caregivers encounter with their car seats relates to space in the backseat. Whether it is due to a small vehicle, a growing family, or vehicle limitations, having enough space for multiple car seats in your backseat can be an issue. With this in mind, the original SlimFit 3-in-1 was introduced several years ago. This narrow and affordable Slimfit model is intended to solve at least some of your carseat space woes and not break your bank account in the process. Let’s take a closer look!

SlimFit 3-in-1 Specs & Features:

  • Rear-facing: 5-40 lbs. and top of head is 1″ below red adjuster handle
  • Forward-facing (with harness): 22-65 lbs and 49″ or less
  • High-back booster: 40-100 lbs. and 43-57″ and at least 4 years old
  • No-rethread harness with 10 position headrest
  • Adjustable base with 4 recline positions (2 for rear-facing, 2 for forward-facing)
  • Steel reinforced frame
  • Energy-absorbing EPS foam
  • Premium push-on lower LATCH connectors (LATCH limit: child weight of 45 lbs.)
  • Dual cupholders which can be rotated away to save space
  • IIHS Best Bet Booster Fit Rating
  • Ten-year expiration date
  • Made in China
  • MSRP $219.99 (although frequently on sale for less)

SlimFit Measurements:

  • Lowest harness height (with infant insert): 7″
  • Highest harness height: 18”
  • Tallest booster height: 18.75″
  • Internal rear-facing height: 27.5” (that’s one inch below the headrest adjustment lever of 28.5” )
  • Crotch buckle positions: 5″, 6.25″, 7.5″
  • Internal seat width: 12″
  • Widest external seat width: 18.5″ (at wings, although if you use both cupholders it is wider at the armrest area)
  • Widest point across armrest area: 17″ (both cupholders retracted) or 19.75″ (both cupholders extended)

Overall, the SlimFit is very similar to what we found in our review of the Graco Milestone, with some minor differences. SlimFit and the Milestone are nearly identical in terms of their features because they are based on the same Graco platform. Above, you can see the Milestone (pink) without its optional single cupholder (left) and the Slimfit with its two cupholders retracted (right). They are so similar, in fact, that I was skeptical about whether the SlimFit really offered any additional advantages over my beloved Graco Milestone 3-in-1. Could I really fit a SlimFit somewhere that I couldn’t fit my Milestone? Could I find a seat that I loved even more than my Milestone? I am happy to say that I think I have!


First of all, the installation of the SlimFit is very easy, just like my beloved Milestone. The instructions are easy to understand and the seat features premium push-on LATCH connectors. Something I particularly liked about the Milestone was the easy access to the rear-facing beltpath. With a quick removal of a tab, you could easily get great leverage for pulling on a shoulder belt or lower LATCH connector strap.

Milestone – undo the “J clip” for better access to the rear-facing beltpath

I quickly found that there is a handy tab on the SlimFit and it is just as easy to access the beltpath. It is not as visible as the tab on the Milestone, but it is just as easy to use.

Access to SlimFit rear-facing beltpath

The SlimFit has the same recline positions as the Milestone: two for rear-facing, one for forward-facing with the harness, and one for forward-facing with the harness or as a belt-positioning booster. In my Subaru Impreza (2010) I was able to install it rear-facing with either of the two recline positions, although the more upright position was almost too upright in my vehicle, according to the level indicator. I was able to install the SlimFit and still fit comfortably in the front seat. I am 5’4″ — your mileage may vary, of course.

Forward-facing, the SlimFit installed easily with either the seatbelt or LATCH.

LATCH Weight Limits
Forward-facing LATCH weight limit: 45 lbs.

Center LATCH installations with Non-Standard Spacing:
Graco allows LATCH installation in the center seating position only if the LATCH anchor bars are spaced 11” apart. That means the center seating position MUST be a dedicated LATCH seating position or one of those rare vehicles where the spacing is *just right*.

Inflatable Seat Belts
Graco has determined that the SlimFit CAN be installed with inflatable seat belts found in some Ford Motor Company vehicles. Other types of inflatable seat belts are still incompatible for use with the SlimFit.

There are no issues when using the seat as a belt-positioning booster.

Installation Next to Other Seats

With only two children, I don’t routinely need to do a 3-across, but I do appreciate the ability to install seats side-by-side on occasion. This allows a third adult to ride in the vehicle, and it makes use of the center position, which is the safest place in the vehicle (provided you can get a good installation) from side-impact collisions. I particularly appreciated being able to install the rear-facing SlimFit in the center when we went on a road trip with a tall (6’3″) travel companion. Since we would be switching drivers, it was important that neither of the front seats were too cramped. I was not going to be switching the car seats around every time we stopped at a rest stop. Putting the SlimFit in the center seating position meant that either of the front seats could be adjusted to a safe (if not ideally comfortable) position for my tall friend.

While the SlimFit definitely fits nicely next to other seats, it is not a guarantee that it alone will solve your space issue. I found that it was very important that the other seats be quite narrow as well. I was able to install the SlimFit next to a Combi Coccoro and an IMMI Go, which are some of the narrowest seats available. Below are two pictures of possible three-across situations involving the SlimFit — one features a forward-facing SlimFit and Diono Radian with a rear-facing Combi Coccoro in the center and the other shows two SlimFits (FF and F) and a Chicco KeyFit carrier (installed without the base).

  SlimFit 3 across

A rear-facing and forward-facing SlimFit could fit side-by-side very nicely. In fact, as you can see in the picture below, they puzzle together so well that in my vehicle they didn’t even touch one another.

Again, all of these configurations were done in my Subaru Impreza, which is not exactly known for its spacious back seat. In some larger vehicles with more room to work with, the options for other seats may be more varied.

Fit to Child

The SlimFit features an optional body support that can be used to provide a better fit for newborns and smaller babies. The body support is required if the baby’s shoulders are below the lowest harness setting but is optional for larger babies. There is also a removable headrest pillow and harness strap covers, both of which have no requirements for use. My children didn’t like the harness strap covers and didn’t need the body support, so we removed those. Both of them liked the headrest pillow and found it to be nice and cushy for sleeping. I do wish that the SlimFit had a buckle pad/cover of some kind, but it’s not a big deal.

My 4.5-year-old is 33 pounds and 39 inches, so she doesn’t meet the minimum weight or height requirements (40 lbs. & at least 43″ tall) for using the Slimfit as a booster. She still rides in a 5-point harness anyway and we’re in no hurry to move her to a booster. However, I did try her in the seat with just the seatbelt to see how the belt fit was. We didn’t drive anywhere but here are a few pics. The belt fit was decent, but I definitely felt like she was too small to use the seat in booster mode (which she is).


The belt guides are easy to use and intuitive, but like many combination/all-in-one seats, it was difficult to reach the seatbelt buckle. My daughter certainly wouldn’t have been able to buckle it on her own, and as the adult, I also found it difficult to reach across to buckle her into her seat.

Converting Between Modes

Moving the LATCH strap from the rear-facing beltpath to the forward-facing beltpath is easy and convenient. The seat has one LATCH strap which slides under a metal bar, making it virtually impossible to get it twisted or backwards in the process. Similar to the Milestone model, the harness components do not have to be removed when you change the seat to booster mode. To convert the seat to booster mode, slide the buckle tongues and chest clip peices together then store them in the convenient storage compartment under the cover. The straps lie cleanly against the back of the seat and do not need to be removed. If you had the seat installed with LATCH, you can even make the switch to booster mode while the seat is still installed. Graco allows you to secure the SlimFit with LATCH while using it in booster mode as long as the installation does not interfere with access to the seatbelt buckle.

Care and Maintenance

The SlimFit cover is relatively easy to remove and is machine washable. The cover is attached mostly with clips and elastic bands and the removal is quite intuitive. Just for fun, before watching any videos or reading the instructions for removal, I timed myself removing the cover. It took me 2 minutes and 15 seconds and didn’t cause me to rip anything or throw a tantrum. The Milestone cover is a little easier to remove, but the SlimFit really isn’t difficult. Re-attaching it wasn’t difficult either, although in the meantime you have to make sure you don’t lose the little white plastic anchors while the seat cover is in the wash.


The Graco SlimFit 3-in-1 is a compact, versatile, affordable seat that fits a wide variety of children. With all the features of the Graco Milestone model (plus dual cupholders!), the SlimFit is a clear winner! The SlimFit also scores an IIHS Best Bet Booster Fit Rating.

So was the SlimFit really more versatile than a Milestone without the cupholder? Yes. I did do some comparison attempts with my Milestone to see if the SlimFit really made a difference and I can say that I was unable to get the same side-by-side installs with the Milestone. The shape of the armrests makes a huge difference. If you are looking for a great seat with virtually all the same great characteristics as the Milestone, but with the added benefits of increased flexibility in narrow spaces, the SlimFit is for you!

Updated Nov. 2022


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