Size & Fit Guides

Kids’ Clothing Size Chart by Age: Newborn to 10–12Y

By MeMe Mae 2 min read
MeMe Mae journal cover for a kids' clothing size chart by age

Few things are trickier than ordering children’s clothing online. Babies and children grow at their own wonderful pace, and age alone rarely tells the whole story. This guide gives you a clear size chart by age, height and weight — from the very first newborn days through to 10–12Y — along with a few gentle rules for choosing the right fit the first time.

How children’s clothing sizes work

Children’s sizes are grouped into two broad stages. Baby sizes are given in months (for example 3–6M or 12–18M) and are based mostly on a baby’s weight and length. Children’s sizes are given in years (2Y, 3Y, and upward) and lean more on standing height. Because every child is different, treat age as a starting point and let height and weight guide the final decision.

Baby size chart (Newborn to 24 months)

Size Age (guide) Height Weight
Newborn 0–3M Up to 24 in / 61 cm Up to 12 lb / 5.5 kg
3–6M 3–6M 24–26 in / 61–67 cm 12–17 lb / 5.5–7.5 kg
6–12M 6–12M 26–29 in / 67–74 cm 17–22 lb / 7.5–10 kg
12–18M 12–18M 29–32 in / 74–81 cm 22–27 lb / 10–12 kg
18–24M 18–24M 32–34 in / 81–86 cm 27–30 lb / 12–13.5 kg

Children’s size chart (2Y to 10–12Y)

Size Age (guide) Height Weight
2–3Y 2–3Y 34–38 in / 86–96 cm 30–33 lb / 13.5–15 kg
3–4Y 3–4Y 38–40 in / 96–102 cm 33–37 lb / 15–17 kg
4–5Y 4–5Y 40–43 in / 102–109 cm 37–41 lb / 17–18.5 kg
5–6Y 5–6Y 43–46 in / 109–117 cm 41–46 lb / 18.5–21 kg
6–7Y 6–7Y 46–49 in / 117–124 cm 46–52 lb / 21–23.5 kg
7–8Y 7–8Y 49–52 in / 124–132 cm 52–60 lb / 23.5–27 kg
8–10Y 8–10Y 52–56 in / 132–142 cm 60–70 lb / 27–32 kg
10–12Y 10–12Y 56–60 in / 142–152 cm 70–85 lb / 32–38.5 kg

These figures are a general guide. Always check the measurements on the individual product page, as fit can vary a little by style.

How to measure your child at home

A soft tape measure and two minutes are all you need:

  • Height: have your child stand straight against a wall, without shoes, and measure from the top of the head to the floor.
  • Chest: measure around the fullest part of the chest, keeping the tape level and comfortably loose.
  • Waist: measure around the natural waistline.
  • Weight: for babies especially, weight is the most reliable guide of all.

When to size up

If your little one falls between two sizes, we almost always suggest choosing the larger one. A touch of growing room keeps beautiful pieces wearable for longer — which matters all the more with heirloom clothing meant to be treasured and, one day, passed down. For milestone outfits bought weeks in advance, remember that babies grow quickly; ordering a size up can save heartache on the day.

A note on buying gifts

Shopping for someone else’s little one? When in doubt, 3–6M is a lovely choice for a newborn gift — it lasts longer than newborn size and is rarely outgrown too soon. Pairing your gift with a gift receipt makes any exchange effortless.

Ready to find the perfect fit? Browse the MeMe Mae collection and use each product’s size details to choose with confidence.

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