Kids Clothing Size Chart: Toddler, Children, Youth & More

Kids clothing sizes run Newborn to 24 Months (0–24 lb) for babies, 2T to 5T (30–45 lb) for toddlers, then numeric sizes 4–20 or letters XS–XL for kids ages 4–15, per the Kids Clothing Size Chart. For example, size 8 fits a 7–8 year-old around 50–53 inches tall, while Youth Large (12–14) fits ages 10–13.

This guide covers every stage: baby sizes, the toddler size chart, girls and boys clothing sizes, dress sizes, letter sizes like Youth Medium and Youth Large, and how US sizes stack up against international ones.

Baby & Newborn Clothing Size Chart

Size	Age	Height	Weight
Preemie	Before due date	Up to 17″	Up to 5 lb
Newborn (NB)	0–1 month	18–21.5″	5–9 lb
0–3 Months	1–3 months	21.5–24″	9–12.5 lb
3–6 Months	3–6 months	24–27″	12.5–17 lb
6–9 Months	6–9 months	27–28.5″	17–21 lb
9–12 Months	9–12 months	28.5–30″	21–25 lb

Notice that “6 month” clothing actually spans two labels — 3–6 Months and 6–9 Months — so a baby exactly six months old could fit either, depending on their weight.

Toddler Size Chart

Size	Age	Height	Weight
12–18 Months	12–18 months	30–32″	26–28 lb
18–24 Months	18–24 months	32–33.5″	28–30 lb
2T	2 years	33.5–35″	30–32 lb
3T	3 years	35–38″	32–35 lb
4T	4 years	38–41″	35–39 lb
5T	4–5 years	41–44″	39–45 lb

2T vs. 24 Months

Both fit a similar height range, but 24 Months clothing is built for a baby who still crawls a lot and wears diapers full-time.
2T is trimmer and made for a child who’s already walking steadily — less bulk, more room to move.

Children’s Clothing Size Chart (Girls & Boys)

Girls’ Sizes

Size	Age	Height	Weight
4	3–4 yrs	38–41″	31–38 lb
5–6	4–6 yrs	41–46″	39–50 lb
6X/7	6–7 yrs	46–50″	50–57 lb
8	7–8 yrs	50–53″	57–65 lb
10	8–10 yrs	53–55″	65–75 lb
12	10–12 yrs	55–58″	75–86 lb
14	12–13 yrs	58–61″	86–100 lb
16	13–14 yrs	61–63″	100–110 lb

Boys’ Sizes

Size	Age	Height	Weight
4	3–4 yrs	39–41″	31–38 lb
5–6	4–6 yrs	42–46″	37–50 lb
6X/7	6–7 yrs	47–50″	48–55 lb
8	7–8 yrs	51–53″	52–64 lb
10	8–9 yrs	53–56″	62–80 lb
12	9–10 yrs	56–58″	75–95 lb
14	10–12 yrs	58–60″	88–98 lb
16–18	12–14 yrs	60–66″	98–115 lb

Youth Letter Size Chart (XS to XL)

Letter Size	Numeric Size	Typical Age	Height
Youth XS	4–6	4–6 yrs	42–50″
Youth S	6–8	6–8 yrs	50–54″
Youth M	8–10	8–10 yrs	54–58″
Youth L	12–14	10–13 yrs	58–62″
Youth XL	16–18	13–15 yrs	62–67″

A kids’ 10-12 in women’s sizing roughly lines up with a women’s XS, since kids’ cuts stay narrower through the chest and hips even at the top of the range. It’s a rough match, not an exact one — women’s patterns shape differently at the waist.

Children’s Dress Size Chart

Size	Height	Chest
2T–4T	33–41″	20–21.5″
4–5	40–45″	21–23″
6–6X	45–48″	23–24″
7–8	48–53″	24–26″
10–12	53–58″	26–30″
14	58–61″	30–32″

Kids Size Chart by Age (Quick Lookup)

1 year — Size: 12M–18M
2 years — Size: 2T
3 years — Size: 3T
4 years — Size: 4T or Size 4
5 years — Size: 5–6
7 years — Size: 7–8
10 years — Size: 10–12
13 years — Size: 14–16

How to Measure Your Child for the Right Fit

Height: Have your child stand barefoot against a wall, feet together, and mark the top of the head.
Chest: Wrap the tape around the fullest part of the chest, kept horizontal.
Waist: Measure the narrowest point, usually just above the belly button.
Inseam: Measure from the crotch seam down to the ankle bone.

Pediatric research shows kids grow roughly 2 to 3 inches a year during early childhood, so re-measuring every season — not just once a year — keeps sizing accurate.

FAQs About Kids Clothing Sizes

What are kids clothing sizes?

They’re standard labels — Newborn through size 20, or XS through XL — based on a child’s age, height, and weight.

Is a 10-12 a youth medium or large?

Most brands mark it as a Youth Medium, though a few size it as a Large.

Are 6 month clothes 3-6 or 6-9?

It depends on weight — “6 months” falls right between the 3–6M and 6–9M sizes.

Will a youth medium fit a 7 year old?

Often yes, since Youth Medium generally covers ages 8–10 and taller 7-year-olds fit that range too.

What is a kids 10-12 in women’s?

It roughly compares to a women’s XS, though the fit through the hips differs.

What age wears a youth L?

Youth Large typically fits kids between 10 and 13 years old.

What are the US sizes for kids?

Newborn through 24 Months, then 2T–5T for toddlers, then 4–20 or XS–XL for older kids.

Henry Collins

I am the admin and author of SizesForm, researching, verifying, and explaining measurements, dimensions, weights, and sizes in simple terms to help readers understand everyday comparisons accurately and confidently.

Kids Clothing Size Chart: Shirts, Pants & Dress Sizes by Age