A hat that fits well stays on in the wind, feels comfortable all day and keeps its shape. This guide shows you how to measure your head, how to read a hat size chart and how to choose between sizes. It works for flat caps, baker boy caps, bucket hats and most other hats.
How to Measure Your Head for a Hat
- Use a soft tape measure. If you only have a ruler, use a piece of string and measure it afterwards.
- Wrap the tape around your head, about 1cm (half an inch) above your eyebrows and ears, and across the widest part at the back of your head.
- Keep the tape snug but not tight, and level all the way round.
- Read the measurement in centimetres or inches.
- Measure twice to be sure, and round up to the nearest size if you fall between two.
Hat Size Chart
Use this as a guide, and always check the chart on the product page, as brands differ.
| Head (cm) | Head (inches) | Size | US hat size | UK hat size |
|---|---|---|---|---|
| 55 | 21 5/8 | S | 6 7/8 | 6 3/4 |
| 56 | 22 | S | 7 | 6 7/8 |
| 57 | 22 1/2 | M | 7 1/8 | 7 |
| 58 | 22 3/4 | M | 7 1/4 | 7 1/8 |
| 59 | 23 1/4 | L | 7 3/8 | 7 1/4 |
| 60 | 23 5/8 | L | 7 1/2 | 7 3/8 |
| 61 | 24 | XL | 7 5/8 | 7 1/2 |
| 62 | 24 3/8 | XL | 7 3/4 | 7 5/8 |
US hat sizes are typically one eighth larger than UK sizes, so check which system a brand uses.
How Should a Hat Fit?
- It should sit level, about a finger's width above your eyebrows.
- It should feel snug but not leave a mark on your forehead.
- You should be able to slide one finger between the hat and your head.
- It should not slide forward or backward when you tilt your head.
Fit Tips by Hat Type
Flat caps and baker boy caps: these should fit closely so they stay put. Wool tweed can relax slightly with wear. See our tweed flat cap guide and baker boy hat guide.
Bucket hats and sun hats: a little room is fine, but wind can catch a loose brim, so a chin cord helps. See our bucket hat guide.
Beanies: they stretch, so choose the size that feels snug, and size up if you want to cover your ears fully. Options include the Tilley Alpine merino beanie and the Deerhunter Recon beanie.
Waterproof hats: make sure you can wear the hat over a thin hat liner or a hood if needed. See our waterproof gloves and hats guide.
What If I Am Between Sizes?
If you are between sizes, go up for hats you will wear with a liner or in cold weather, and go down for stiff fabrics that will not stretch. Check the returns policy if you are unsure.
Hat Size FAQs
How do I measure my hat size? Wrap a soft tape around your head above your eyebrows and ears and across the back of your head.
What is a medium hat size? Medium is typically about 57 to 58cm, or US hat size 7 1/8 to 7 1/4, but sizing varies by brand.
What is the difference between US and UK hat sizes? US sizes are generally one eighth larger than UK sizes for the same head.
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