This is a great guide to finding your hat size, where you’ll learn to take your measurement to find the perfect fit, and also convert between US, UK and European sizes.
This conversion chart is for both men and women – look here for children’s hat sizes.
How to measure your hat size
1. Wrap a tape measure around your head just above your ears and at the center of your forehead. The tape should fit comfortably – not too tight. You can also use a piece of string and then measure it with a regular ruler.
2. Once you have your measurement in either inches or centimeters, check your size in the chart below. If you’re unsure, choose the higher size.
Hat size converter – men and women
| Inches | Cm – Euro | US size | UK size | XS-XL |
|---|---|---|---|---|
| 19 4/8 | 50 | 6 1/4 | 6 1/8 | XXS |
| 19 7/8 | 51 | 6 3/8 | 6 1/4 | XXS |
| 20 2/8 | 52 | 6 1/2 | 6 3/8 | XXS |
| 20 3/4 | 53 | 6 5/8 | 6 1/2 | XS |
| 21 1/4 | 54 | 6 3/4 | 6 5/8 | XS |
| 21 5/8 | 55 | 6 7/8 | 6 3/4 | S |
| 22 | 56 | 7 | 6 7/8 | S |
| 22 1/2 | 57 | 7 1/8 | 7 | M |
| 22 3/4 | 58 | 7 1/4 | 7 1/8 | M |
| 23 1/4 | 59 | 7 3/8 | 7 1/4 | L |
| 23 5/8 | 60 | 7 1/2 | 7 3/8 | L |
| 24 | 61 | 7 5/8 | 7 1/2 | XL |
| 24 1/2 | 62 | 7 3/4 | 7 5/8 | XL |
| 24 3/4 | 63 | 7 7/8 | 7 3/4 | XXL |
| 25 1/4 | 64 | 8 | 7 7/8 | XXL |
Find the right hat size
Some hats, like baseball caps, may have a little bit of stretch in the fabric, so you may want to size down if you’re in between sizes. Other models, like fedoras or straw hats, may not have much give in the material, so you may want to size up.
A well-fitting hat should sit comfortably on your head without feeling too tight or too loose. It should also be secure enough to stay on your head in windy conditions, but not so tight that it leaves a mark on your forehead.
Please observe that this is only a guide to find your hat size, sizes may vary between different manufacturers.
FAQ – Hat sizes
Are there different sizing standards for hats in different countries?
Yes, hat sizing varies around the world. US/Canada sizing uses a numeric system based on the circumference of the head in inches divided by Pi (roughly 3.14). UK sizing uses a similar scale, but the sizes run about ⅛ smaller. European (metric) sizing is simply the head circumference in centimeters.
What should I do if my head measurement falls between two sizes?
If you’re between two sizes, consider the hat style. Stretchy hats, like knit caps, can go smaller. For stiff hats, like fedoras or straw hats, go with the larger size.
What does “one size fits all” mean for hats?
These hats have an adjustable strap or elastic band, so they fit most head sizes. They are a good choice if you are unsure of your size.
Does hat size differ between men and women?
No, adult hat sizing is unisex. The same size chart applies to both men and women — it’s purely based on head circumference.
What is the most common hat size for men and women?
For men, the most common size is around 57–58 cm or size M. For women, it is slightly smaller, around 55–57 cm (size S–M).
How do I know if a hat fits correctly?
A well-fitting hat should sit about one finger-width above your eyebrows, feel snug but not tight, and stay in place without leaving a red mark on your forehead after removal.
Can my hat size change over time?
Yes. Weight gain or loss, age, and even hairstyle changes can affect your head size. It’s a good idea to measure again if it’s been a while.
Do baseball caps fit differently than other hats?
Yes. Most baseball caps come in fitted sizes or have an adjustable strap at the back. For fitted caps, use the size chart as normal. For adjustable caps, one size usually fits most adults.