What is my hat size in UK and US sizing?

Millinery works in centimetres, and a UK size runs an eighth of an inch smaller than the US size for the same head. 54 cm is UK 6 5/8 and US 6 3/4. 56 cm is UK 6 7/8 and US 7. 57 cm is UK 7 and US 7 1/8. 58 cm is UK 7 1/8 and US 7 1/4. 59 cm is UK 7 1/4 and US 7 3/8. 61 cm is UK 7 1/2 and US 7 5/8.

What should I do if I am between two hat sizes?

Take the larger size. A hat slightly too big can be brought in with a sizing ribbon by any milliner and will still sit level, while one slightly too small presses at the temples and leaves a mark on the forehead. If the occasion matters, commission the piece to your own measurement instead.

Is there a hat size rule for Royal Ascot?

In the Royal Enclosure a woman's hat or headpiece must have a solid base of at least 10 cm in diameter, so a slim band or a small bow does not meet it. A pillbox or any shape with a proper crown answers the rule. Ascot reviews its dress code each year, so check the current published guidance.

Hat Size Guide: How to Measure, UK and US Sizes

Q: How do I measure my head for a hat?

Run a soft tape measure around your head about one centimetre above the ears and across the middle of the forehead, keeping it level the whole way round and snug without pulling tight. Read it in centimetres; that number is your hat size. Measure over the hair you expect to wear on the day, because a chignon or thick hair can add a centimetre.

Every piece is made by hand in London, so fit matters more here than it does on a shelf. Measure once, properly, and you will know your size for every hat you ever buy.

How do I measure my head for a hat?

Run a soft tape measure around your head where a hat actually sits: about one centimetre above the ears and across the middle of the forehead. Keep the tape level the whole way round and snug without pulling it tight. Read the measurement in centimetres. That number is your hat size.

Two things change the reading. Measure over the hair you expect to wear on the day, because a chignon or thick hair can add a centimetre. And take the measurement twice, since most people are half a centimetre out on the first attempt.

What size am I in UK and US hat sizes?

Millinery works in centimetres. British and American hat sizes are fractions of an inch, and the two are not the same: a UK size runs an eighth smaller than the US size for the same head.

54 cm — UK 6 5/8 — US 6 3/4
55 cm — UK 6 3/4 — US 6 7/8
56 cm — UK 6 7/8 — US 7
57 cm — UK 7 — US 7 1/8
58 cm — UK 7 1/8 — US 7 1/4
59 cm — UK 7 1/4 — US 7 3/8
60 cm — UK 7 3/8 — US 7 1/2
61 cm — UK 7 1/2 — US 7 5/8

Our listings always give the centimetre range, so a piece described as 57 to 59 cm fits a 58 cm head comfortably.

What do the size names mean?

54 to 55 cm — Small
56 to 57 cm — Medium, the most common fitting
58 to 59 cm — Large

What if I am between two sizes?

Take the larger of the two. A hat slightly too big can be brought in with a sizing ribbon by any milliner, and it will still sit level. One that is slightly too small presses at the temples, leaves a mark on the forehead and becomes unbearable by the middle of the afternoon. If you are between sizes and the occasion matters, commission the piece to your own measurement instead.

How should a hat sit when it fits?

Level, about one finger's width above the ears, staying put when you turn your head and lifting away without leaving a red line. If it moves when you look down it is too large. If you can feel it after ten minutes it is too small.

Do headbands and headpieces need a size?

No. Headbands, bows and veiled headpieces are one size and shaped to sit securely on any head. Several pieces are built on a band that is colour matched to your own hair, so the band disappears and only the design is seen. Browse the headbands and fascinators.

Is there a size rule for Royal Ascot?

Yes, and it catches people out. In the Royal Enclosure a woman's hat or headpiece must have a solid base of at least 10 cm in diameter, so a slim band or a small bow will not meet it. A pillbox or any shape with a proper crown answers the rule. Check the base measurement of a piece before you commit, and read the current year's published guidance, since Ascot reviews the wording each season. Start in the Royal Ascot collection.

Can a piece be made to my exact measurement?

Yes. Every piece can be blocked to your own measurement on commission, in any colour, and fitted in the London atelier or by video call if you are abroad. Tell us your measurement and the occasion and Monika will take it from there. Begin a commission.