Omni Calculator logo

Hat Size Calculator

Created by Łucja Zaborowska, MD, PhD candidate
Reviewed by Bogna Szyk and Jack Bowater
Last updated: Jan 18, 2024


What size hat am I? If this question has been wandering around your head for some time now, our hat size calculator may offer you the perfect answer. 🎩

Computing children's, women's, and men's hat sizes with our calculator will take you less time than it did to read this sentence — it's just that simple!

Follow the article below to discover hat size conversion charts and your hat sizes in inches — using both the American & British versions. 👒

How to calculate your hat size?

In order to discover your hat size, you need to take a measurement of the circumference of your head and use one of the hat size charts. Be careful! American sizes are usually greater than British ones.

  • Range of international sizes: XS-S-M-L-XL-XXL-XXXL;
  • Range of American sizes: 6 1/2 - 8 1/8; and
  • Range of British sizes: 6 3/8 - 7 7/8.

🧢 International sizes for children are based on their age.

This may have left you wondering — hat size vs. circumference — how are they related? Move on to the next section of the text to find out!

How to measure the head for a hat?

Hat sizes are based on head circumference. To measure it correctly:

  1. Take a measuring tape.
  2. Find the part that protrudes the most at the back of your head and connect it to the most protruding part of your forehead using the measuring tape, leaving a gap of approximately 0.4-0.8 in (1-2 cm) above your ears.
  3. Complete the circumference and write down the result.

💡 7 3/4 hat size doesn't equal the 7 3/4 inch head circumference.

Looking for the tiniest of hats? 👶 Go ahead and check your baby's head circumference percentile.

How to use the hat size calculator?

Wondering what the 24-inch hat size is? Search no more!

Enter your head circumference into our hat size calculator and obtain your results immediately — you may choose from 6 different length units, including both metric and imperial systems.

Have you already found your hat size? How about checking out our other clothing tools:

Shoe size calculator 👞 | Jacket size calculator 🧥| Jeans size calculator 👖 | Bra size calculator 👙

What's the adult hat size chart?

Here are the American and British hat size charts:

Head circumference

International size

US size

UK size

20.5 in / 52 cm

XS

6 1/2

6 3/8

20.9 in / 53 cm

XS

6 5/8

6 1/2

21.3 in / 54 cm

S

6 3/4

6 5/8

21.7 in / 55 cm

S

6 7/8

6 3/4

22 in / 56 cm

M

7

6 7/8

22.4 in / 57 cm

M

7 1/8

7

22.8 in / 58 cm

L

7 1/4

7 1/8

23.2 in / 59 cm

L

7 3/8

7 1/4

23.6 in / 60 cm

XL

7 1/2

7 3/8

24 in / 61 cm

XL

7 5/8

7 1/2

24.4 in / 62 cm

XXL

7 3/4

7 5/8

24.8 in / 63 cm

XXL

8

7 3/4

25.2 in / 64 cm

XXXL

8 1/8

7 7/8

Below is the children's hat size chart:

Head circumference

Age

US size

UK size

15.7 in/ 40 cm

0-6 months

5

4 7/8

16.5 in/ 42 cm

0-6 months

5 1/4

5 1/8

17.3 in/ 44 cm

6-12 months

5 1/2

5 3/8

18.1 in/ 46 cm

6-12 months

5 3/4

5 5/8

18.9 in/ 48 cm

12-24 months

6

5 7/8

19.7 in/ 50 cm

24-48 months

6 1/4

6 1/8

20.5 in/ 52 cm

4-8 years

6 1/2

6 3/8

21.3 in/ 54 cm

4-8 years

6 3/4

6 5/8

Using the charts above, you can find answers to the following questions and many, many more:

  • What hat size is a large/ medium/ small? 🎓
  • What hat size is 24 in? ⛑️
  • What is a large hat size in inches? 👑

FAQ

What hat size is 23 inches?

L, 7 3/8, or 7 1/4 if using international, American, and British sizes, respectively. A head circumference of 23.2 in / 59 cm corresponds to different sizes according to each country's hat size chart.

What if my head circumference falls between two hat sizes?

If you measured your head circumference and this measure falls in between two different sizes, it is recommended that you choose the larger size since it can be modified to produce a better fit.

Łucja Zaborowska, MD, PhD candidate
My hat is meant for
an adult
Head circumference
in
Check out 26 similar clothing and sewing calculators 👗
BagBelt sizeBikini body shape… 23 more
People also viewed…

Boat speed

Determine the top speed of the boat from its power and displacement.

Korean age

If you're wondering what would your age be from a Korean perspective, use this Korean age calculator to find out.

Plastic footprint

Find out how much plastic you use throughout the year with this plastic footprint calculator. Rethink your habits, reduce your plastic waste, and make your life a little greener.

Sock size

Use this sock size calculator to find the perfect sized sock, whether you are male, female, or looking for socks for your child.
Copyright by Omni Calculator sp. z o.o.
Privacy, Cookies & Terms of Service