Head Size Chart: Head Circumference by Age and Hat Size

Hat size calculator

Your head circumference

Or pick an age

Enter your head measurement to see your size in every system.

Head size by age

Head size by age
Age	cm	Inches	US
Preemie	25 – 32	9.8 – 12.6	–
Newborn	32 – 36	12.6 – 14.2	–
0 to 3 months	35 – 40.5	13.8 – 15.9	–
3 to 6 months	39.5 – 43.5	15.6 – 17.1	–
6 to 12 months	42 – 47	16.5 – 18.5	–
Toddler (1 to 2 years)	45 – 49	17.7 – 19.3	–
2 to 4 years	47.5 – 51	18.7 – 20.1	–
5 to 8 years	50.5 – 53	19.9 – 20.9	6 ⅜ – 6 ⅝
9 to 12 years	52 – 55.5	20.5 – 21.9	6 ½ – 7
Teen	54 – 58	21.3 – 22.8	6 ¾ – 7 ¼
Adult woman	53 – 59.5	20.9 – 23.4	6 ⅝ – 7 ½
Adult man	55 – 60.5	21.7 – 23.8	6 ⅞ – 7 ⅝

Adult head size and hat size
cm	Inches	US	UK	Letter
46	18 ⅛	5 ¾	5 ⅝	–
47	18 ½	5 ⅞	5 ¾	–
48	18 ⅞	6	5 ⅞	–
49	19 ¼	6 ⅛	6	–
50	19 ⅝	6 ¼	6 ⅛	–
51	20 ⅛	6 ⅜	6 ¼	–
52	20 ½	6 ½	6 ⅜	XS
53	20 ⅞	6 ⅝	6 ½	XS
54	21 ¼	6 ¾	6 ⅝	S
55	21 ⅝	6 ⅞	6 ¾	S
56	22	7	6 ⅞	M
57	22 ½	7 ⅛	7	M
58	22 ⅞	7 ¼	7 ⅛	L
59	23 ¼	7 ⅜	7 ¼	L
60	23 ⅝	7 ½	7 ⅜	XL
61	24	7 ⅝	7 ½	XL
62	24 ⅜	7 ¾	7 ⅝	XXL
63	24 ¾	7 ⅞	7 ¾	XXL
64	25 ¼	8	7 ⅞	3XL
65	25 ⅝	8 ⅛	8	3XL
66	26	8 ¼	8 ⅛	3XL

How to measure your head

1 Use a soft tape measure, or a string and a ruler.
2 Wrap it around your head where the hat will sit: about 1 cm (⅜ in) above your ears and across the middle of your forehead.
3 Keep the tape level and snug, not tight. Do not pull it in.
4 Read the number where the tape overlaps. Measure two or three times and use the largest value.
5 Type the number into the calculator, or find it in the chart.

Frequently asked questions

What is a big head size?

For adults, a head over about 61 cm (24 in), which is a hat size 7 ⅝ or larger.

What is a small head size for an adult?

Under about 54 cm (21 ¼ in), which is a hat size 6 ¾ or smaller.

How do I measure my head size?

Wrap a soft tape around the widest part of the head, just above the eyebrows and ears, and read the number.