This Viral TikTok Might Explain Why Baby's Clothes Don’t Fit Right

Just like women’s jeans, baby clothes sizing can be a frustrating guessing game. Your tiny tot might wear 4M in Carter’s onesies and be busting out of their 6M Janie and Jack pants. While there’s certainly room for interpretation among brand sizing, one mom is sharing the truth bomb you might not have expected when it comes to getting the best fit for baby.

A mom to 5-month-old Beckham and 4-year-old Bryn, Rachel Woolsey, always thought she “had the biggest babies” as they always fit in the size up from what they should’ve been in—or so she thought. The mom of two reveals she actually has misunderstood the way baby clothing sizes work.

“I had sizing wrong the whole time. If something says 6 months, it doesn’t mean you start putting them in it at 6 months, it means you have up to 6 months of them fitting in it,” she says in the video. “Like what?! How did I not know this? I am over here like, dang we got a big boy, we got a future athlete on our hands. No, we got an average boy with a stupid mom. I’m really hoping I get the comment saying ‘oh my gosh, I didn’t know that either so I don’t feel so dumb.”

As suspected, thousands of people weren’t clued into this little-known secret behind baby clothing sizes. The video, which now has over 4.3 million views on TikTok, has a variety of reactions and comments.“I am a mom of four…I didn’t know this,” wrote one parent. Another added, “I’m glad I’m watching this being pregnant with my first, thank you for teaching me.”

Not all parents were so keen to take Woolsey’s word. “My kiddos always started wearing the size after they hit that age. So I think it’s an estimate,” wrote one user, “ I don’t think that’s right,” added another.

Your baby’s fit may vary, as all babies are different, but Woolsey is indeed espousing the truth. According to experts like Hanna Andersson’s chief product officer Kara Carter and Giggle CEO and founder Ali Wing, up through 24M, baby clothes sizes refer to the maximum age range for that size. For example, if the item is labeled as 9M, it’s not meant for 9-month-olds and up but rather infants ages 6-9 months.

When baby turns two, though, the rules shift. Toddler clothes sizes refer to the minimum. Toddler sizes are meant to last the entire year until their next birthday, since kiddos this age aren’t experiencing growth spurts at the same pace as infants. “The 24 months size is designed for babies up to 24 months. On the other hand, 2T is created for toddlers between 2 and 3 years old,” Carter explains. So if you are like Wooley and are tired of getting excited about baby’s upcoming outfit just to be disappointed when they have outgrown it, keep in mind this rule of thumb.