Ultimate Kid Clothing Size Chart guide: Find the Perfect Fit

You’ll find a great fit for your kids much faster if you use a kids’ clothing size chart as your go-to guide. Because boys and girls develop such different body shapes as they grow taller, comparing their current measurements against these charts and the tips shared below is a must. It gives you a much better feel for what size your kids actually need. This way you can shop with confidence.

Kids’ Clothing Size Chart by Age

Unisex Infant Sizing Chart (Boys & Girls)

Size	Age Range	Height (in / cm)	Weight (lb / kg)	Chest (in / cm)
0-3M	0–3 Months	20.5–24 in / 52–61 cm	8–12 lbs / 3.6–5.4 kg	15.5–17 in / 39–43 cm
3-6M	3–6 Months	24–27 in / 61–68.5 cm	12–16 lbs / 5.4–7.3 kg	17–18 in / 43–45.5 cm
6-9M	6–9 Months	27–29 in / 68.5–73.5 cm	16–20 lbs / 7.3–9.1 kg	18–18.5 in / 45.5–47 cm
12M	9–12 Months	29–30 in / 73.5–76 cm	18–22 lbs / 8.2–10 kg	18.5–19 in / 47–48 cm
18M	12–18 Months	30.5–33 in / 77.5–84 cm	22–26 lbs / 10–11.8 kg	19–20 in / 48–51 cm
24M	18–24 Months	33–35 in / 84–89 cm	26–30 lbs / 11.8–13.6 kg	20–21 in / 51–53 cm

Unisex Toddler Sizing Chart (Boys & Girls)

Size	Age Range	Height (in / cm)	Weight (lb / kg)	Chest (in / cm)	Waist (in / cm)
2T	2 Years	33–35 in / 84–89 cm	29–33 lbs / 13–15 kg	20–21 in / 51–53.5 cm	20.5–21.5 in / 52–55 cm
3T	3 Years	35–38 in / 89–96.5 cm	32–36 lbs / 14.5–16.3 kg	20.5–21.5 in / 52–55 cm	21–22 in / 53–56 cm
4T	4 Years	38–41 in / 96.5–104 cm	35–39 lbs / 16–17.7 kg	21.5–22.5 in / 54.5–57 cm	21.5–22.5 in / 54.5–57 cm

Kids’ & Youth Sizing: Boys vs. Girls (Standard Fit)

Size	Girls’ Height (in)	Boys’ Height (in)	Girls’ Chest (in)	Boys’ Chest (in)	Girls’ Waist (in)	Boys’ Waist (in)	Girls’ Hips (in)	Boys’ Hips (in)
4/ XS	41–42	41.1–43	22.5–23.5	22–23	21–22	21–21.5	23.5–24.5	23–24
5/S	42–44.5	43.1–45	23.5–24.5	23–24	22–23	21.5–22	24.5–25.5	24–25
6/S	44.5–47	45.1–47.5	24.5–25.5	24–25	22.5–23.5	22.5–23	25.5–26.5	25.5–26.5
7/S	49–51.5	47.6–50	26–27.5	25.5–26.5	23.5–24	23–23.5	27.5–28.5	26.5–27.5
8/M	51.5–53.5	50.1–53	27.5–29	26.5–27.5	24–24.5	24–24.5	28.5–30.5	27.5–28.5
10/M/L	53.5–56	54–57	29–30.5	28–29.5	25–26	25–25.5	31–33	29.5–30.5
12/L	56–59	57.1–60	30.5–32.5	29.5–31.5	26–27.5	25.5–27	33–35	31–33
14/XL	59–61.5	60.1–63	32.5–34.5	31.5–33.5	27.5–29.5	27–29	34.5–36.5	33–35
16/XL/XXL	61.5–63.5	63.1–66	34–36	33.5–35.5	29–31	29–31	37–39	35–37
18/XXL	63.5–65.5	66.1–68	35.5–37.5	35.5–37.5	30.5–32.5	31–32.5	39–41	37–39

Industry Insight: While standard teen sizes for boys and girls appear similar on paper, the cut of the garment is where they differ. Boys’ standard fits are typically straighter, while girls’ fits allow for more curvature. For children who don’t fit the “standard” rectangular block, always check the Slim, Plus, or Husky measurements in our clothing chart for girls and our clothing chart for boys.

Kids’ Sizing by Clothing Comparison

This comparison chart shows the standard baseline for each category. While the numerical ranges are similar, the measurement focus highlights why choosing a gender-specific or specialized fit becomes important as children grow. For more detailed measurement for each age range you can look at our full individual guides.

Category	Boys Range	Girls Range	Measurement Focus
Tops	Chest: 23–39.5″	Chest: 22.5–40.5″	Boys: Shoulder width & torso length Girls: Bust development & waist taper
Bottoms	Waist: 21–37″	Waist: 20.5–38″	Boys: Seat rise & husky/slim waist room Girls: Hip-to-waist ratio & hip curvature
Inseam	Length: 17–32″	Length: 17–32″	Both: Measured from crotch to floor
Dresses	—	Ages 4–18	Girls: Bodice fit & total hem length

FAQs

What Size is 8 in Children’s Clothes? 

A size 8 is a standard Medium (M) for both boys and girls. It is for big kids. Most brands use 8 as the main size for children aged 8 to 10 who need more room than the little kids section.

Is Size 7 a Youth Small or Medium?

 Size 7 is a Medium (M). Size 6 is usually where the “Small” group ends. When you hit 7, the patterns get longer and wider to fit a growing child. This makes it the entry-point for medium clothing.

Is a 5T the Same as a 4? 

No. A 5T is for toddlers, so it’s got a wider, bulky bottom for diapers. A regular size 4 is way slimmer and longer. This is because it’s made for kids who don’t wear pull-ups anymore.

What Size is Kid M? 

A Kid M usually covers sizes 8 to 10. It’s the standard fit for kids between 8 and 12 years old. If a kid is tall for their age, they might move into this range earlier, around age 7 or 8.

Final Words

While most industry charts follow a set standard for sizing, kids have their own unique way of growing. Comparing a kids’ clothing size chart with your kids’ actual measurements and following the tips above is the most reliable way to pick the right fit. It also saves you plenty of time and frustration.

If you want to find their next standout outfit, browse the collection at Siukid. They offer high-end, trendy clothing for kids. It is made to handle daily play while keeping that boutique look. When kids have a wardrobe that fits well, it will help them stay active and feel their best.