The Right Fit

Infant Car Seat Fit Recommendations

Aria + Mesa V2 + Mesa Max

Feeling lost or confused when it comes to fitting your child in their new car seat? Wondering if your little one is in the right kind of car seat? Not sure what the “pinch test” is? You’re not alone! We’re here for you, so you can be there for your kids.

With the help of a few of our UPPAbaby babies, we’ll guide you through, step by step, so you can identify the proper ways to fit your own child, know when to transition, and feel confident buckling in your little one, from day one.

As a reminder, always refer to your car seat and vehicle manual as your primary source of information. There are many things to consider when placing your child in the right seat. If you have additional questions on child fit, please don’t hesitate to reach out to our Customer Experience team at support@uppababy.com.

Let’s get started!

  • Closeup of smiling baby in infant car seat with proper headrest and harness placement. Sketch highlighting the headrest and harness locations of infant car seat overlays the image.

    Headrest + Harness

The headrest and harness are interconnected, so when you adjust the headrest, the harness positioning will follow. The headrest should be positioned so that the harness slots are placed at or slightly below the child’s shoulders. The bottom of the headrest ears will appear to be touching the child’s shoulders to ensure proper harness fit. The harness straps should be snug against the child’s shoulders. Conduct the pinch test on top of the shoulders to ensure no webbing can be gathered.

Headrest Positioning

  • Infant in car seat showcasing correct headrest and harness position. Harness straps are placed at or slightly below her shoulders, the top of the baby's head is positioned more than 1″ from the top of the headrest structure, and the bottom of the headrest ears appear to be touching the child’s shoulders (lines drawn on top of image to highlight where bottom headrest ears lay)

    Meet Noah, she is 2.5 months, 23” and 12lbs 10 oz. She is properly positioned in the headrest because the harness straps are placed at or slightly below her shoulders and the top of her head is positioned more than 1″ from the top of the headrest structure.

  • Incorrect headrest and harness position for infant in car seat. Bottom of the headrest and harness straps are positioned too high, which makes the harness straps sit above shoulders and the headrest more than 1” from the top of baby's head.

    Here Noah is not positioned correctly in the headrest. The bottom of the headrest and harness straps are positioned too high; therefore, the harness straps are above her shoulders, not at or below. When positioned correctly, the headrest should not be more than 1” from the top of her head.

Harness Tightness

  • Correct harness position. Car seat is properly fitted to infant so that there is no webbing slack around torso or hip area indicating the harness has been properly tightened.

    Say hi to Wells! He is 9 months, 27.5” and 17lbs and 14oz and is properly positioned in his car seat as there is no webbing slack around his torso or hip area indicating the harness has been properly tightened. A pinch test is a simple method to double check if you have achieved proper tightening. See the Q&A section below to learn more on how to conduct a pinch test.

  • Incorrect harness position. Harness is improperly fit to infant, too much slack is present in both the torso and hip area and the chest buckle is positioned too low

    In this photo, Wells is not fit properly. The pinch test indicates that too much slack is present in both the torso and hip area. This excess slack needs to be removed, so that the harness straps can be properly tightened on Wells.

    Additionally, the chest clip is positioned too low. Please refer to the Chest Clip section for proper fit.

  • Sketch illustrating pinch test. Child sitting in car seat with improper harness fit, parent's hand is seen pinching and gathering slack between fingers, showing fit is too loose.

    How do I make sure the harness is tight enough through the Pinch Test?

    The “Pinch Test” is the simplest way to figure out if your child’s harness is tight enough. First, place your fingers on the harness by the child’s shoulders and try to pinch the webbing. If you can pinch and gather slack between your fingers, that means the harness is not tight enough. If you cannot get the strap to pinch between your fingers, that means the harness is tight enough.

    Watch our How-To video on The Pinch Test

  • Infant sitting in car seat with correct headrest and harness placement. Baby is seen smiling while holding car seat showing the comfort and safety of the fit.

    Is it ok that my child’s head looks snug in the headrest?

    Yep! The headrest was designed to contain a child’s head in the event of a side impact collision. Like a helmet, the closer the energy-absorbing material is to the head, the better protection.

    Cole is 11 months, 28″, 20.5 lbs

  • Infant sitting in infant car seat with the proper fit and no harness pads.

    Do I always need to use harness pads?

    Nope! Harness pads are totally optional.

    Please Note: They must be removed when securing a preemie. The priority is getting the chest clip at armpit level and the harness tight enough. If the harness pads prevent this from happening, then they should be removed.

    Wellington is 4 months, 26.25″ and 14lbs 11.5oz

Questions?

We’re here to help – get support from our Customer Experience Team.

  • Closeup of baby in infant car seat with proper chest clip placement. Sketch highlighting the chest clip on an infant car seat overlay the image.

    Chest Clip

The chest clip must be at armpit level. This ensures that the harness is in the right position should a crash occur.

Chest Clip Positioning

  • Correct position of chest clip on infant in car seat. Green circle showing correct fit - chest clip is properly positioned at armpit level, centered on chest, and securely clipped together.

    Meet Wells again! He is 9 months, 27.5” and 17lbs 14 oz. His chest clip is properly positioned at armpit level. It is centered on his chest and securely clipped together.

    Additionally, the harness is tightened properly.

  • Incorrect position of chest clip on infant in car seat. Red circle showing error - chest clip positioned below armpit level.

    Here Wells’ chest clip is not properly positioned as it is clearly lower than armpit level.

    Additionally, the harness is too loose.

  • Infant smiling as they are properly and safely fit in car seat with chest clip at armpit level

    Why does the chest clip need to be at armpit level?

    The chest clip is a pre-crash positioner. It properly positions the harness on your child’s collar bone. The chest clip placement and the tightness of the harness help prevent ejection in a frontal crash.

    Wells is 9 months old, 27.5” and 17lbs 14oz

Questions?

We’re here to help – get support from our Customer Experience Team.

  • Closeup of baby in infant car seat with crotch buckle placement. Sketch highlighting crotch buckle location on infant car seat overlays the image.

    Crotch Buckle

The crotch buckle should rest securely against the child with no gaps. If gapping is present on smaller infants, a crotch roll is permitted. The child should not be sitting on top of the buckle. The harness straps should be snug around the hips.

Crotch Buckle Positioning

  • Correct crotch buckle positioning. Infant in car seat, closeup showing correct crotch buckle placement as it rests securely against baby with no gaps

    Meet Wellington! He is 9.5 months, 29” and 18lbs 13oz. In this photo the crotch buckle is correctly positioned because it rests securely against him with no gaps.

  • Incorrect crotch buckle positioning. Infant in car seat, closeup showing infant sitting on top of crotch buckle due to use of Infant Insert when child is too large.

    Here the crotch buckle is not properly positioned because the infant insert has not been removed from the seat which is causing Wellington to be incorrectly sitting on top of the buckle. Wellington is too big to be using the infant insert.

  • Infant securely in car seat with harness straps snug over the infant’s thigh

    Is it ok to have a gap between the harness and thighs?

    Harness straps should be snug over the infant’s thigh, like in the example of Siggy on the right. Keeping the harness snug on the body reduces motion in the event of a crash.

    Siggy is 6 weeks, 21.5″ and 8lbs 13oz

  • Closeup of infant in car seat with proper positioning of the crotch buckle. The crotch buckle is flush against the child’s lower body

    Is it ok if my child is sitting on top of the crotch buckle?

    The crotch buckle should be flush against the child’s lower body, like in the example of Wellington to the right. Keeping the harness snug on the body reduces motion in the event of a crash. While using the infant insert, it may need to be removed if the child is sitting on top of the buckle.

Questions?

We’re here to help – get support from our Customer Experience Team.

  • Closeup of infant insert attached to infant car seat. Sketch highlighting location of infant insert on car seat overlays the image.

    Infant Insert

The robust infant insert is designed to provide better fit and body positioning for infants approximately 4-11 lbs.

Infant Insert Positioning

  • Correct positioning of infant insert. Infant in car seat, infant car seat is correctly positioned under the baby, supporting infant's torso

    Say hello to Ledger! He is 3 weeks, 19” and 8lbs the infant insert is correctly positioned under Ledger, helping to provide better fit and positioning for his 8lb body. In the image, you can see his torso is properly supported.

  • Incorrect fit of baby in car seat. Infant incorrectly positioned in car seat due to small size, use of the infant insert would support the baby and allow for the proper car seat fit

    In this photo Ledger is not using the infant insert and thus, he is not correctly positioned because of his small size. At just 8lbs, he should still be using the infant insert to provide better fit and positioning. In the image, you can see his torso is not properly supported.

  • Side by side Mesa Max Infant car seats, one with infant insert seat and one without infant insert

    Can I keep using the infant insert if my child is over 11 lbs?

    Depends! We understand that all babies are different. If your child fits comfortably and properly with the infant insert, then using it over 11 lbs is permitted as a positioning tool. If your child is sitting on top of the buckle where it is pulling away from their lower body, that is an indication the infant insert is no longer needed.

    Note: For comparison, the infant insert is shown in the Mesa Max on the left, and it is not included in the Mesa Max on the right.

  • Closeup of infant sitting on top of the crotch buckle, indicating, he is the correct size to fit without the insert

    When should I remove the infant insert?

    When your child starts sitting on top of the buckle and it pulls away from their lower body.

    In the example to the right, Wellington is 9.5 months, 29” and 18lbs 13oz and is sitting on top of the crotch buckle; therefore, he is the correct size to fit without the insert.

Ensure Optimal Comfort for Your Child:

We’ve received feedback that some children are not sitting comfortably in the Mesa Max Infant Car Seat after the infant inlay is removed. To improve the fit for a wider range of infants, we are offering a complimentary two-piece foam kit. Sign up here to receive your foam kit and enhance your child’s comfort.

Family, First.

Whether it’s via Email, Text, Call, Live Chat, Video Chat, or Virtual Consultation, our exceptional Customer Experience Team is here to help you all day, every day, in every way. At UPPAbaby, we put you and your family first.

As a reminder, always refer to your car seat and vehicle manual for weight and height requirements. If you’re still unsure or just have additional questions, please don’t hesitate to reach out to our Customer Experience team at: support@uppababy.com!