Key Takeaways
- Measure your head, then divide by pi. Head circumference in inches divided by 3.14 is your fitted hat size. A 22 inch head is a size 7.
- Average adult head is 22 3/8 inches, a fitted size 7 1/8, or Medium.
- Fitted caps are exact; flexfit covers two sizes in a stretch band; adjustable snapbacks fit most adults.
- Custom embroidery does not change the fit of a structured cap.
- Between sizes? Size up, a touch of room beats a cap that pinches.
How to Measure Your Hat Size
Hat size starts with one number: the circumference of your head. Wrap a soft tape measure around your head where a cap naturally sits, about an inch above your eyebrows and the top of your ears, across the widest part of the back of your head. Keep the tape snug but not tight and parallel to the floor, and take the measurement twice. No tape handy? Wrap a piece of string, mark it, and measure the string against a ruler. Enter the number above in inches or centimeters and the calculator gives you a fitted size and an S to XL cap size instantly.
Hat Size Chart
Head circumference to fitted size to cap size. Find your measurement and read across.
| Head circumference (in) | Fitted size | Cap size |
|---|---|---|
| 20 1/2 | 6 1/2 | XS |
| 20 7/8 | 6 5/8 | XS |
| 21 1/4 | 6 3/4 | S |
| 21 5/8 | 6 7/8 | S |
| 22 | 7 | M |
| 22 3/8 | 7 1/8 | M |
| 22 3/4 | 7 1/4 | L |
| 23 1/8 | 7 3/8 | L |
| 23 1/2 | 7 1/2 | XL |
| 23 7/8 | 7 5/8 | XL |
| 24 1/4 | 7 3/4 | 2XL |
| 24 5/8 | 7 7/8 | 2XL |
| 25 | 8 | 3XL |
Fitted, Flexfit, and Adjustable Caps
- Fitted. One exact size with no adjuster. The most precise fit, so measure carefully and order the size the calculator gives you.
- Flexfit or stretch-fit. A spandex band covers two fitted sizes in one cap, labeled S/M or L/XL. Forgiving if you are between sizes.
- Adjustable, snapback, or strapback. A strap or snap adjusts the fit, so one size fits roughly 21 to 24 inch heads. The easiest choice for a mixed team.
For team caps, adjustable styles keep your order simple, while fitted caps give a cleaner look when you know everyone's size. Arklavo embroiders custom caps in all three with no minimums. Get a quote when you are ready.
Save your hat size card
Email yourself your fitted and cap size with the full chart, plus an extra no minimums your first custom cap order. Grab it here.
Hat Size FAQ
Wrap a soft tape measure around your head where a hat sits: about an inch above your eyebrows and ears, across the widest part of the back of your head. Keep it snug but not tight, parallel to the floor. Take the number in inches or centimeters and enter it above.
A fitted hat size is your head circumference in inches divided by pi (about 3.14). So a 22 inch head is a size 7. Sizes step up in eighths: 7, 7 1/8, 7 1/4, and so on. Caps are also labeled S to XL, which group two fitted sizes each.
The average adult head is about 22 3/8 inches, which is a fitted size 7 1/8, or Medium. Men average around 7 1/4 to 7 5/8, and women around 6 7/8 to 7 1/4. Always measure rather than guess, since heads vary widely.
A 22 inch head circumference is a fitted size 7, which falls in the Medium band for adjustable and stretch-fit caps.
A fitted cap is one exact size and does not adjust, so measure carefully. A flexfit or stretch-fit cap covers two fitted sizes in one band (S/M or L/XL). A snapback or adjustable cap fits roughly 21 to 24 inches and adjusts with a strap, so most adults take one size.
No. Embroidery and custom logos do not change the fit. A structured six-panel cap fits true to its labeled size whether it is blank or decorated. Unstructured and dad-cap styles can feel slightly roomier.
Youth caps usually fit head circumferences of about 20 to 21 1/2 inches, and toddler sizes about 18 to 20 inches. Most kids caps are adjustable. Measure the child the same way and size up if they are between sizes.
Either works. Toggle the unit above. To convert yourself, divide centimeters by 2.54 to get inches. A 56 cm head is about 22 inches, a fitted size 7.
Last updated June 30, 2026
Sources and Further Reading
- Standard US headwear sizing: fitted hat size equals head circumference in inches divided by pi, the basis of the chart above.
- Cap manufacturer spec sheets for the structured six-panel, flexfit, and adjustable styles Arklavo decorates.
- Fit note: heads vary in shape as well as size. When between sizes, size up, and choose adjustable or flexfit for a mixed team.