How to Determine Your Hat Size

Measuring Your Head

Wrap a length of string around your head. Locate a piece of string or twine that is about 25 inches (64 cm) long. Place 1 end of the string in the middle of your forehead, and wrap it around your head. You want the string to rest about 0.5 inches (1.3 cm) above your ears, right where you’d like the hat to sit on your forehead. This can also be done with a sewing tape measure.

Pinch the string. Grab the place where the string meets back up with the center of your forehead (and the other end of the string) with your thumb and forefinger. Remove the string from your head without losing this spot. You may want to cut the string at this location to make measuring easier.

Lay your string next to a ruler. Lay the string down flat without losing your spot. Use a ruler to determine the length of the string (and size of your head.) Write down this measurement so you won't forget. Your measurement needs to be accurate down to ⁄8 inch (0.32 cm). If you used a sewing tape measure, you can skip this step.

Translate this number into a hat size. Many hats are sized generally (small, medium, large). Some hats will have more specific sizes ranging from 6 ¾ to 8+. Reference a size chart to determine your hat size based on your measurement. Here are some guidelines: 21.125–21.5 inches (53.66–54.61 cm) = Small or sizes 6 ¾ - 6 ⅞. 21.875–22.25 inches (55.56–56.52 cm) = Medium or sizes 7 - 7 ⅛. 22.625–23 inches (57.47–58.42 cm) = Large or sizes 7 ¼ - 7 ⅜. 23.5–23.875 inches (59.69–60.64 cm) = X-Large or sizes 7 ½ - 7 ⅝. 24.25–24.625 inches (61.60–62.55 cm) = XX-Large or sizes 7 ¾ - 7 ⅞. 25–25.375 inches (63.50–64.45 cm) = XXX-Large or sizes 8 - 8+.

Trying on Hats

Visit a hat shop. Locate a hat shop in your area, and pay them a visit. Check out different hat styles that you might be interested in, and try on many hats. Bring a friend with you to get a second opinion on what looks good. You can also do this with hats you have at home.

Find a hat that feels comfortable. Try on hats in a variety of sizes until you find one that feels right. You might even ask a sales associate to help you find a hat that fits you properly.

Note the size. When you find a hat that fits, look at the size. Many hats will be sized as small, medium, large, or extra large. Some hats will have more specific sizes, ranging from 6 ¾ to 8+. Try to figure out both your general hat size, as well as your more specific hat size. It can be important to know both. This isn't an exact science. There will be some variation from brand to brand.

Choosing a Hat When You Fall between Sizes

Choose the larger size. Whether you’ve measured your head, tried on hats, or both, you might find that you fall in between sizes. If this happens to you, you should always round up. Hats generally shrink. They don’t stretch.

Add “filler” to your hat. You can purchase hat filler from almost any hat shop. Hat filler consists of foam lining that is adhesive on one side. You can stick 1, 2, or 3 pieces of hat filler into your hat to help make it the perfect size for you. If you don’t want to do this yourself, an associate at your local hat shop can probably do it for you. The hat lining attaches to the sweatband of the hat. Hat lining is generally not removable. Attempting to remove it yourself could damage the hat.

Shrink your hat with moisture and heat. Hats are prone to shrinking over time. If your hat is a little too big, you can speed up this process. Use a squirt bottle to mist your hat with water, then leave it in a warm place for several hours (such as near a heat vent or inside a hot car). Repeat this method 2-3 times until your hat feels right.