Hat Size Guide: How to Measure Your Head for a Hat

Buying a hat online comes with one nagging worry: what if it doesn't fit? It's the single biggest reason people hesitate, and it's easily solved. You need one number, and you can have it in about thirty seconds.

This guide covers how to measure your head, a full hat size chart converting centimetres to inches and numeric sizes, and — the part that actually matters: how our caps and hats are each sized, because they aren't all the same.

How to measure your head for a hat

You need a soft tape measure. If you haven't got one, a length of string and a ruler will do.

1. Wrap the tape around your head where the hat will actually sit: roughly 1cm above your ears, and across the middle of your forehead. Not up on the crown, and not down on your eyebrows.
2. Keep it snug, not tight. The tape should sit flat against your head without digging in. If you're pulling, it's too tight.
3. Read the measurement in centimetres. This is the number that matters.
4. Measure twice. If you get two different readings, take the larger one.

Using string? Wrap it round, mark where it overlaps, then hold it flat against a ruler.

Most adult heads land between 54cm and 62cm. Write your number down. Everything else follows from it.

Hat size chart: cm, inches and numeric sizes

Where do those odd fractions come from? A numeric hat size is your head's diameter in inches, not its circumference. Take the circumference in inches, divide by pi, and you get the number on the label. It's a leftover from the days when hatters measured the wooden blocks they shaped hats on, and it has survived for well over a century, which is very British of it.

One honest caveat. You'll find charts online claiming UK sizes run an eighth smaller than US sizes, and others treating them as identical. Traditional British hatters did historically cut an eighth below the American scale, but it isn't applied consistently across the trade today. This is exactly why we quote centimetres: a centimetre is a centimetre wherever you shop. Use your cm measurement against the retailer's own chart, not the number printed in your last hat.

Quick conversions

• A 6 7/8 hat size is 55cm.
• A 7 1/8 hat size is 57cm.
• A 7 1/4 hat size is 58cm.
• A 7 3/8 hat size is 59cm.
• A 7 1/2 hat size is 60cm.
• A 7 5/8 hat size is 61cm.

How our hats are sized (this is the important bit)

Here's the part most size guides skip, because most size guides aren't written by the people posting you the hat.

Our hats are not all sized the same way. Some are one size with give in them. Some come in small, medium and large and don't adjust at all. Knowing which is which is the difference between a hat that fits and a return.

Soft caps: usually one size, with an elasticated back

Most of our flat caps and newsboy caps are built with an elasticated back that stretches to your head. There's nothing for you to adjust and a centimetre either way won't trouble them. Some are sold in fitted sizes instead, including the Carlyle Heath range and a handful of our padded caps. If a cap shows a size picker, use it; if it does not, it is one size.

The Classic Arthur Tweed Flat Cap relaxes at 57cm and stretches to 60cm. The Carlyle Tweed Herringbone Newsboy Cap sits at 58cm up to 60cm.

Note those aren't identical, and they vary a little across the range, so check the fit range on the individual product page. It's stated on every one. As a rule of thumb, if you measured between 57cm and 60cm our one-size caps will fit you comfortably.

Structured hats: choose your size, because they don't adjust

This is where measuring genuinely matters. Trilbies and pork pie hats have a firm crown that sits on your head rather than moulding to it, so they come in small, medium and large — and once you've chosen, that's the size.

The Elwood Tweed Trilby comes in small (56cm), medium (58cm) and large (60cm). The Doyle Felt Pork Pie Hat comes in small (57cm), medium (59cm) and large (60cm).

The breakpoints differ slightly between styles, so don't assume you're a medium in everything. Take your measurement to the product page and match it there.

If you're deciding between the two styles in the first place, our guide to the difference between a trilby and a fedora and our pork pie hat guide will both help.

Felt hats with a sweatband ribbon

Some felt hats split the difference: one size, but with an adjustable grosgrain ribbon inside the sweatband. The Classic Colour Felt Fedora is built around 58cm and the ribbon lets you tune the fit from there.

Knitted hats: they'll fit

Beanies and snoods stretch to almost anyone. If sizing anxiety is what's been stopping you buying a hat at all, start with a beanie and worry about none of the above.

Still choosing a style? Our complete guide to hat types and their names is the place to start, and if you're torn between the two most popular caps, we've compared newsboy caps and flat caps.

Caught between two sizes? Size up

If your measurement falls between two sizes — and on a trilby or pork pie it very well might, because the sizes step in 2cm or 3cm jumps — go up, not down.

The reasoning is simple. A hat that's slightly loose can be padded out with a strip of hat sizing tape inside the sweatband, in about a minute, for very little money. A hat that's too tight cannot be fixed. It will give you a headache and a red line across your forehead, and you will stop wearing it.

A well-fitting hat should feel secure but not gripping. Wear it for ten minutes and take it off: if there's a mark on your forehead, it's too small. It shouldn't lift in a breeze, and it shouldn't need pushing back into place every few minutes.

One last thing worth knowing: wool and tweed relax slightly with wear, so a snug cap will settle over its first few outings. Felt gives much less. Don't buy a felt hat a size down hoping it will stretch, because it won't do you the favour.

Measuring a child's head

Same method, smaller number, and one extra piece of advice: measure, don't guess from their age. Children's head sizes vary enormously at the same age, and a hat bought a size too big ends up on the floor of the car.

Our junior styles include the Arthur Kids Flat Cap and the Junior Tweed Panel Newsboy Cap, and the rest are in our kids' collection. The fit range is stated on each product page.

Frequently asked questions

What is a 7 1/4 hat size in cm?

A 7 1/4 hat size is 58cm. That's a medium in most of our structured hats, and comfortably within range for our one-size caps.

What is the average head size for a man?

Most adult men measure between 57cm and 60cm, which is a hat size of roughly 7 1/8 to 7 1/2, or a medium to large.

What is the average head size for a woman?

Most adult women measure between 54cm and 57cm, or a hat size of around 6 3/4 to 7 1/8. If you're at the lower end of that, a strip of sizing tape will make a one-size cap sit perfectly.

Are your hats one size or do they come in sizes?

Both, depending on the style. Most flat caps and newsboy caps are one size with an elasticated back, but some, including the Carlyle Heath range, come in fitted sizes. Trilbies and pork pie hats come in small, medium and large and do not adjust. Always check the individual product page, where the fit is stated.

Is hat size the same as cap size?

Both are based on the circumference of your head. The practical difference is that caps have more give, so they're far more forgiving of a centimetre either way.

Can a hat be stretched or taken in?

Taken in, easily: sizing tape inside the sweatband will reduce the fit by a size or so. Stretched, not really. A little steam will persuade a wool cap to relax slightly, but don't count on more than a fraction. This is why you size up rather than down.

How do I stop a hat blowing off?

Nine times out of ten, a hat that blows off is a hat that's too big. Measure properly and the problem tends to solve itself.

Now you know your size

You've got your number, and you know whether the style you want is one-size or sized. That was the hard part.

Browse the full range in hats and caps, or go straight to classic flat caps, newsboy caps, trilby hats, fedora hats, pork pie hats or beanie hats.

And if you're still unsure, tell us your measurement and we'll tell you honestly which size to take. It's a quicker conversation than a return.