The hat size guide converts your head circumference to US hat size, UK hat size, EU hat size, and S/M/L/XL cap size. Includes measuring instructions and a complete reference chart.
Find Your Hat Size
Hat Size Chart
| US Size | UK Size | EU Size | Inches | cm | Cap Size |
|---|
How to Find Your Hat Size
Hat sizes look confusing at first — US sizes like "7 1/4" are actually fractions of inches representing the diameter of the hat opening (circumference ÷ π). Fortunately, you only need your head circumference to find the right size.
Step 1: Measure your head
Use a soft measuring tape, not a rigid ruler. Place the tape about half an inch above your eyebrows and ears — this is where a hat's brim sits. Measure all the way around. If you don't have a measuring tape, use a string, then measure the string against a ruler.
Step 2: Find your size
Enter your measurement in the converter above, or look it up in the chart. If you're between sizes, go up to the larger size — you can always add hat sizing tape inside to make a slightly large hat fit snugly.
Understanding US hat sizes
US hat size 7 means the inside diameter is 7 inches (circumference ÷ π). Size 7 = 22 inches circumference = 56 cm. The US sizing goes up in eighths of an inch: 6 3/4, 6 7/8, 7, 7 1/8, 7 1/4, etc. Average adult male: 7 1/4 (58 cm). Average adult female: 6 7/8 (55 cm).
FAQ
Is this hat size guide free?
Yes, completely free with no signup required.
How do I measure my hat size?
Wrap a flexible measuring tape around your head about 1/2 inch above your eyebrows and ears — this is where a hat sits. Keep the tape horizontal and snug but not tight. Take the measurement in both inches and centimeters. If between sizes, size up for a comfortable fit.
What is the average hat size for adults?
The average US adult male hat size is 7 1/4 (58 cm circumference). The average US adult female hat size is 6 7/8 (55 cm). Hat sizes follow a distribution — most adult sizes fall between 6 7/8 and 7 5/8, so most commercial hats fit this range.
What do S, M, L, XL mean for hats?
Small typically covers sizes 6 7/8-7 (55-56 cm). Medium covers 7-7 1/8 (56-57 cm). Large covers 7 1/4-7 3/8 (58-59 cm). XL covers 7 1/2-7 5/8 (60-61 cm). These vary by brand — always check the specific size chart since an 'L' from one brand may be an 'XL' from another.
What is the difference between fitted and snapback/adjustable hats?
Fitted hats come in specific sizes (7, 7 1/4, 7 1/2, etc.) and require knowing your exact hat size. Snapback and adjustable hats use a strap/closure that adjusts from about size 6 3/4 to 7 5/8. Fitted hats offer the best look and feel; adjustable hats work for most head sizes without measuring.