Hat Size Guide UK 2026: What Size Hat Am I? How to Measure Your Head (CM & Inches Chart)

Buying a hat online is easy until the size question appears. Is a medium in a fedora the same as a medium in a baker boy cap? What does 58 cm actually mean? And what happens if your head sits between two sizes? This guide from Hopoye answers all of it for UK shoppers: how to measure your head correctly, a full UK hat size chart in centimetres and inches, and practical fitting advice for every style we sell, from wool fedoras to adjustable baseball caps.

How do I measure my head for a hat?

Wrap a soft tape measure around the widest part of your head, sitting about 1 cm (half an inch) above your ears and across the middle of your forehead, just above your eyebrows. Keep the tape snug but not tight, and read the measurement in centimetres. That number is your hat size.

No tape measure? Use a piece of string or a phone charging cable, mark where it meets, then lay it flat against a ruler. Measure two or three times and take the largest reading; hair volume and tape tension both nudge the number, and a hat that is slightly roomy is far more comfortable than one that squeezes.

• Position: 1 cm above the ears, mid forehead, around the bump at the back of your head.
• Tension: snug enough not to slip, loose enough to slide one finger underneath.
• Hair: measure with your hair as you normally wear it under a hat.

What size hat am I? The UK hat size chart

Once you have your head measurement in centimetres, match it to the chart below. This is the sizing Hopoye uses across our fitted headwear, and it lines up with standard UK hat sizing used by most British retailers.

Sizing bands can shift by a centimetre between brands and materials, so treat the chart as your baseline and check the size option listed on each product page. Hopoye fitted hats state their range on every listing, and our sized styles run from XS through to 2XL depending on the design.

What is the average head size in the UK?

The average UK adult head measures around 57-58 cm for men and 55-56 cm for women, which is why medium is the most commonly bought hat size in Britain. Men most often take an M or L; women most often take an S or M. Teenagers typically fall between 54 and 57 cm, overlapping the adult XS to M range.

Averages are only a starting point though. Head sizes in the UK genuinely span 53 cm to beyond 64 cm, and guessing from averages is the single biggest cause of hat returns. Sixty seconds with a tape measure removes the guesswork entirely.

Should I size up or down if I am between hat sizes?

Size up. A hat that is slightly loose can be worn comfortably all day and can be tightened with foam sizing tape tucked behind the sweatband, but a hat that is too tight presses on your temples, leaves a red band across your forehead, and often causes headaches. There is no comfortable fix for a hat that is genuinely too small.

How should a hat fit?

A well fitted hat sits level on your head, rests about 1 cm above your ears and eyebrows, and grips gently all the way round without pressure points. You should be able to slide one finger between the hat and your forehead, and the hat should stay put when you tilt your head forward and shake it gently.

Signs a hat is too small: a red line on your forehead after ten minutes, the hat perching high on your crown, or temples that ache. Signs it is too big: the brim dropping over your eyebrows, the hat spinning freely, or wind lifting it with no resistance. Style also plays a part; our guide to which hat suits your face shape covers how brim width and crown height flatter different features once the size is right.

What if a hat does not come in sizes? Adjustable and one size hats explained

Around half of all headwear sold in the UK is one size fits most with a built in adjuster, and for these you do not need a measurement at all. Baseball caps use a velcro strap, snapback or buckle at the rear; docker hats adjust with a fold and internal fit; boonie hats use a drawcord. A typical adjustable hat covers roughly 55-61 cm, which fits the vast majority of UK adults.

Adjustable styles are the safe choice if you are buying a gift and cannot measure the recipient's head. These Hopoye favourites all adjust:

Plain Baseball Cap, 27 Colours

Velcro adjuster, from £7.00

Navy Cotton Docker Hat

Adjustable fit, from £10.00

Khaki Boonie Sun Hat

Drawcord adjuster, from £15.00

Do different hat styles fit differently?

Yes. The same head measurement can feel different from style to style because crown depth, stiffness and brim weight vary. Here is how the main Hopoye ranges size up:

• Wool fedoras (sized XS-XL): structured felt with minimal stretch, so measure first and follow the chart exactly. Our 100% wool fedoras come in fifteen colours across XS to XL; the full range is in our fedora buying guide.
• Baker boy and newsboy caps (sized S-2XL): the eight panel crown adds volume, so they feel roomier than a flat cap at the same size. See the herringbone baker boy or the multi check patchwork baker boy, and our Peaky Blinders style guide for how to wear them.
• Baseball, trucker and docker caps (adjustable): one size fits roughly 55-61 cm. The mesh trucker cap uses a snapback; dockers use a fold adjust.
• Boonies, bucket hats and sun hats: mostly one size with a drawcord or elastic; softer fabrics forgive a centimetre either way.

Can I make a hat smaller or bigger?

You can make a hat up to about 1 cm smaller easily: self adhesive foam hat sizing tape (a few pounds online) sticks behind the internal sweatband and takes up the slack invisibly. Folded paper towel tucked behind the sweatband works as a temporary fix.

Making a hat bigger is harder. Wool felt can be stretched slightly with a hat stretcher or by wearing it over a folded towel while it dries after light steaming, but there are limits and structured hats can distort. This is another reason to size up when in doubt. For care that protects the fit you already have, see our guides to washing a baseball cap without ruining the shape and cleaning and reshaping a straw hat, plus how to pack a hat in a suitcase so it arrives the size and shape it left.

Frequently asked questions about UK hat sizes

What is the most common hat size in the UK?

Medium (57-58 cm) is the most common UK hat size, followed by large. Around two thirds of British adults fall between 56 and 60 cm.

How do I measure my head without a tape measure?

Wrap string, ribbon or a charging cable around your head 1 cm above your ears, mark where it overlaps, then measure the length flat against a ruler.

Are men's and women's hat sizes different in the UK?

No, hat sizing is unisex and based purely on head circumference in centimetres. Women's heads average about 2 cm smaller, so women more often take S-M and men M-L, but the chart is identical.

What size is 58 cm in UK hat sizes?

58 cm is the top of a medium. In traditional fitted sizing it corresponds to 7 1/8. In a rigid material such as wool felt, many people at 58 cm prefer a large.

Do hats stretch over time?

Soft cotton, knitted and unstructured hats relax slightly with wear; structured wool felt and stiffened caps barely stretch at all. Never rely on stretch to fix a hat that is tight out of the box.

What hat size should I buy as a gift if I cannot measure?

Choose an adjustable style such as a baseball cap, trucker cap, docker hat or drawcord boonie. One size adjustable hats fit roughly 55-61 cm, which covers most UK adults.

Is a 62 cm head big for a hat?

62 cm is an XL, larger than average but well within normal range. Hopoye's sized baker boy caps run to 2XL (63-64 cm), and adjustable caps at full extension suit most heads up to about 61-62 cm.

Once you know your measurement, buying is simple: check the size option on the product page, size up if you sit on a boundary in a structured style, and go adjustable when in doubt or gifting. Start with our sized wool fedoras and vintage baker boy caps, or the one size adjustable baseball caps in 27 colours. And if your feet deserve the same precision as your head, our UK sock size guide has you covered from the ankles down.