Hat Fit Guide

Nowadays, the majority of hats are created in “one size fits most” models, which will generally accommodate all but the largest and smallest head sizes. However, some hats are still available in a range of sizes to provide a more customized and comfortable fit. In the following guide, we’ll provide some helpful tips on how to measure your head and choose a hat size that will work for you.

Before You Start

When it comes to measuring your head, the best tool for the job is a flexible measuring tape used by tailors and seamstresses. This type of measuring tape is usually made of soft vinyl and will not stretch. If you don't have access to a tailor’s measuring tape, you can use a piece of string or ribbon. Just make sure whatever you use doesn’t stretch, or you may not get an accurate measurement. Quick Tip: Whether you measure the circumference of your head in inches or centimeters is up to you. However, centimeters are easier for getting an accurate measurement, since the units are smaller.

How To Measure Your Head


Start by wrapping the tape or string around the circumference of your head at the same location you would normally wear a hat — usually about an inch above the eyebrows and just above the ears. Hold the leading edge of the tape against your forehead with one hand. Use your other hand to bring the rest of the tape around your head until it overlaps the leading edge. Pull the tape snug and, with two fingers, pinch it just beneath the overlap point. Hold it firmly so that your forefinger marks the overlap point. Remove the tape and note the length on a piece of paper. You may want to measure two or three times to ensure you get an accurate measurement. If you’re having difficulty measuring your head size by yourself, ask a family member or friend to assist you. If you’re using string, the process is the same, except you will need a traditional measuring tape or ruler to measure the length of the string. Finally, refer to the chart below to find your ideal hat size.

Hat Size Conversion Chart

US Numeric Size Alpha Size Inches CM
6¾ – 6⅞ S 21¼ – 21⅝ 54 – 55
7 – 7⅛ M 22 – 22⅜ 56 – 57
7¼ – 7⅜ L 22¾ – 23⅛ 58 – 59
7½ – 7⅝ XL 23½ – 24 60 – 61
7¾ – 7⅞ 2X 24⅜ – 24¾ 62 – 63
8 3X 25⅛ 64

Note: Only use this chart if you are unable to find brand-specific sizing information for the hat you're buying. Hat size conversions can vary slightly from brand to brand.

A Quick Note on "One Size Fits Most" or "O/S"

Hats labeled as O/S (One Size Fits Most) will fit most adults and some youth. Most O/S hats are either adjustable or have a stretchable headband. O/S sizes vary slightly by manufacturer and may not fit everyone.