🔧 Utility Loft

Utility Loft → Hat Size Converter

Hat Size Converter

Convert between US, UK, EU, and S/M/L hat sizes. Measure your head circumference or enter a size you already know — the match appears instantly.

Enter your head circumference above to see your hat size in every standard.

Tip: measure where the hat sits — a finger-width above the ears. Between sizes? Size up.

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Hat size chart

US, UK, EU, and alpha sizes side by side with the head circumference each maps to.

USUKEU (cm)S / M / LCircumferenceInches
6⅝54XS53.9 cm21.2 in
6⅞55S54.9 cm21.6 in
76⅞56S55.9 cm22.0 in
7⅛757M56.9 cm22.4 in
7⅛58M57.9 cm22.8 in
7⅜59L58.9 cm23.2 in
7⅜60L59.8 cm23.6 in
7⅝61XL60.8 cm24.0 in
7⅝62XL61.8 cm24.3 in
7⅞63XXL62.8 cm24.7 in
87⅞64XXL63.8 cm25.1 in

US size = head diameter in inches (circumference ÷ π). EU size = circumference in cm. Brands vary slightly; check the maker's chart for stiff-brim styles.

Frequently asked questions

How do I measure my head for a hat?

Wrap a soft tape measure around the widest part of your head — about a finger-width above your ears and mid-forehead, where a hat naturally sits. Keep it level and snug but not tight. Note the number in centimeters or inches and enter it above. If you don't have a soft tape, use a piece of string and measure it against a ruler.

How do US hat sizes work?

A US fitted hat size is literally your head's diameter in inches — the circumference divided by π. So a 22-inch head circumference is about a size 7 (22 ÷ 3.14 ≈ 7). That's why US hat sizes look like 6¾, 7, 7⅛, and so on, rising by an eighth at a time.

What is my EU hat size?

European hat sizes are simply your head circumference in centimeters. A 57 cm head is an EU 57. It's the most direct system — measure your head in cm and that number is your size.

How do UK and US hat sizes differ?

UK sizes run about ⅛ smaller than US sizes for the same head. A US 7¼ is a UK 7⅛. The converter handles the offset so you don't have to.

What if I'm between two hat sizes?

Size up. A hat that's a touch loose can be taken in with foam sizing tape or an adjustable band, but one that's too tight will leave a mark and won't sit right. For beanies and stretch-fit caps, the exact number matters less.