How to Measure Your Head for a Hat: The Complete UK Hat Size Guide (2026)

A hat that fits properly is the difference between something you wear every day and something that lives at the back of a drawer. The good news? Getting your size right takes about a minute and a piece of string. This is the complete UK guide to measuring your head and choosing the right hat size — with a full cm-to-size chart, the average sizes for men and women, and simple fixes for hats that sit too loose or too tight.

Below you'll find the step-by-step method, a printable-style size chart, how sizing differs between fitted hats and adjustable ones, and what to do if you fall between two sizes. Let's get you measured.

🧵 How to measure your head for a hat (step by step)

You only need a soft tailor's tape measure. Don't have one? Skip down to the string method — a shoelace and a ruler work just as well.

1. Find the right spot. Position the tape around the fullest part of your head: about a centimetre above your eyebrows at the front, above your ears at the sides, and around the bump at the back of your skull. This is the line a hat naturally rests on.
2. Keep it level. Make sure the tape isn't slanting up or down around your head. A tilted tape is the most common reason people get the wrong number.
3. Snug, not tight. Pull the tape so it's comfortably firm against your head — about as tight as you'd want the hat to feel. You should be able to slip one finger underneath. Don't squeeze.
4. Read it in centimetres. Note where the tape meets. Centimetres are easier than inches for hat sizing, so use the cm side.
5. Measure twice. Do it two or three times and take the largest consistent reading. Heads aren't perfectly round, so a second measurement keeps you honest.

No tape measure? Use the string method

Wrap a piece of string, a shoelace or a phone-charging cable around your head following the same line described above. Mark or pinch the point where it overlaps, then lay it flat against a ruler or tape and read the length in centimetres. That's your number.

📐 UK hat size chart: cm to S/M/L (and fitted sizes)

Once you have your head measurement, match it to the chart below. We've included letter sizes (XS–XXL), traditional fitted hat sizes (the 6¾, 7, 7⅛ numbers you'll see on structured hats), and a rough guide to who each size tends to suit.

🇬🇧 What's the average hat size in the UK?

There's a lot of natural variation, but here's where most adults sit:

• Average men's hat size (UK): most men measure between roughly 57 cm and 60 cm, which is a Medium to Large. If you're not sure where to start, Medium is the safest first guess for men.
• Average women's hat size (UK): most women measure between roughly 54 cm and 57 cm, a Small to Medium. Small is the most common women's size.
• Children: kids' heads vary enormously with age, so measuring is essential. Many of our kids' straw hats are a one-size 54 cm fit, comfortable for a lot of younger children — but always measure first (see the children's section below).

Remember: these are starting points, not rules. Your tape measure beats any average.

🎩 Fitted vs adjustable: how different hats fit

Not every hat uses the same sizing system. Some are cut to a specific size, others are designed to fit a range of heads. Knowing which is which saves a lot of guesswork.

Structured hats: fedoras, trilbies & pork pies (sized XS–XL)

Wool felt hats hold a fixed shape, so they're sold in proper sizes. Use the chart above and, if you're caught between two, size up — a felt hat that's a fraction loose can be padded, but a tight one is uncomfortable all day. Our handmade wool fedoras come in a full XS–XL range, and the crushable wool trilby is a great forgiving option. For more on choosing between the classic shapes, see our wool fedora guide.

Handmade Wool Trilby HatFrom £22.99 100% Wool Fedora HatFrom £24.99 100% Wool Pork Pie HatFrom £24.64

Adjustable hats: baseball & trucker caps

Most baseball caps and trucker caps are 'one size fits most,' using a strapback, snapback or buckle at the rear to tighten the fit. If your measurement is roughly 54–62 cm, an adjustable cap will almost always fit. The main thing to check is the closure type — snapbacks adjust in fixed steps, while sliders and buckles fine-tune more precisely. Our full baseball cap style guide breaks down the options.

Outdoor hats: boonie & fisherman hats (adjustable)

Boonie and bucket-style outdoor hats usually fit a broad range and add a drawcord or chin strap so they stay put in the wind — handy for fishing, hiking and dog walks. The Premium Fisherman Boonie and Waterproof Hikers Boonie both use an adjustable chin strap, so exact head size matters less. See our boonie & fisherman hat guide for the full range.

Premium Fisherman Boonie HatFrom £10.99 Waterproof Hikers Boonie HatFrom £10.99 Ladies Straw Sun HatFrom £9.99

One-size & stretch hats: berets, bucket hats, straw sun hats, baker boy caps

Plenty of styles are designed to fit most adults without sizing:

• Berets are soft and naturally stretchy, so one size fits the majority — it's more about how you shape and angle them. See how to wear a beret.
• Bucket hats are often sold as one-size or in S/M and L/XL. Our reversible bucket hats give you two looks in one and fit a generous range.
• Straw sun hats tend to be crushable one-size styles with a wide brim that shades your face and neck — easy to pack and forgiving on fit. Browse the sun hat collection.
• Baker boy & newsboy caps usually fit a wide range thanks to their panelled, slightly slouchy shape. The PU leather baker boy cap is a good year-round example.

🤔 What if I'm between two hat sizes?

This is the most common sizing question, and the answer depends on the hat:

• Structured wool hats (fedora, trilby, pork pie): size up. You can easily pad a slightly loose felt hat with foam sizing tape, but you can't shrink a tight one comfortably.
• Caps and outdoor hats: choose an adjustable style and the in-between problem disappears entirely.
• Right on the boundary (say, exactly 57 cm): think about hair and comfort. Lots of hair or planning to wear it in cold weather over an ear-warmer? Size up.

🔑 How to make a hat smaller (so it stops slipping down)

Bought a hat that sits a touch low or spins around? You don't need to return it. The classic fix is a hat size reducer — a strip of self-adhesive foam tape you stick inside the sweatband. It's cheap, invisible once worn, and takes a hat down roughly half to one full size depending on how much you use. For caps, simply tighten the rear strap. For the future, an adjustable style is the foolproof choice.

↔️ Do hats stretch? How to loosen a tight hat

A little. Wool felt and knitted styles relax slightly with wear and mould to your head over the first few outings. If a felt hat feels marginally snug, you can gently stretch it by easing the sweatband outward with your hands, or by placing something round and slightly larger inside overnight. Hard-structured hats won't stretch much, though — so if a hat is genuinely too tight, size up rather than fight it. Knitted beanies and berets are the most forgiving of all.

👶 How to measure a child's head for a sun hat

Children rarely sit still for measuring, so do it quickly: wrap a soft tape (or string) around the widest part of their head, just above the ears and eyebrows, and read it in centimetres. Compare that to the product's size details. Many of our kids' straw sun hats are a one-size 54 cm fit with a wide brim that shades the face and neck — comfortable for a lot of younger children, but measuring first is always the safest move. As a sun-smart habit, pair a wide-brim hat with shade during the hottest part of the day.

Kids Butterfly Straw Sun HatFrom £6.99 PU Leather Baker Boy CapFrom £15.00

❓ Hat sizing FAQs