How to Measure Your Hat Size

Ever wondered why simply throwing on a baseball cap or cute sun hat wasn’t always a one-and-done deal? While there’s not as much of a size difference between hat sizes compared to pant or shirt sizes, they’re not all going to fit and flatter every single head. Learning how to measure for your correct hat size helps narrow down options and gets you into a better fit. 

While some hats come with adjustable features, you’ll need to know specific measurements when ordering custom-made hats or hats that need to sit just right on your head—like a cowboy hat, floppy sun hat, or fancy derby hat. To know which size to pick, you’ve got to measure your head. Here’s how. 

How to Measure Hat Size

Follow this quick and easy step-by-step guide on how to measure for hats. All you need is a single measurement. 

1. Grab the Essentials 

Grab a soft tape measure and pencil and paper, says Mark Carmona, style expert and founder of Sunday Swagger. (Alternatively, you can jot your measurements in a notes app on your phone.) Carmona says that if you don’t have a soft tape measure, you can use a string and then measure the string against a ruler.

2. Stand in Front of the Mirror 

It’s best to stand in front of the mirror when measuring your head for hats. This helps you see what you’re doing and ensures the tape measure runs in a straight line. Better yet, enlist a friend to help you out. It’ll only take a few seconds of their time. 

3. Measure Your Forehead 

Starting at the center of your forehead, wrap the measuring tape across the middle of your forehead, just above your eyebrows. Loop it around your entire head until it overlaps in the front. The overlap point is what your measurement is. 

“Your tape measure, or string, should rest where the brim of your hat would sit,” Carmona says. This is usually the widest part of the head. The measurer should run straight around your head (parallel to the ground) and not be loose or too tight. Carmona suggests measuring twice to ensure accuracy. 

4. Write Down Your Hat Measurements 

Some brands use metric units (centimeters) while others use imperial units (inches). Jot down both so they’re easily accessible. Note that most people’s hat measurement falls between 51 and 64 centimeters, or 20 to 25 inches.  

5. Refer to the Brand’s Sizing Guide  

Every hat brand has its own sizing guide, so refer to the brand’s guide to find your correct size. For example, some simply use a small, medium, large sizing while others go by numeric sizes. If you have your forehead circumference measurement in inches/centimeters then you’ll be able to figure out the correct size quickly using the brand’s chart. 

When between sizes, the rule of thumb is to round up to the nearest size so the hat doesn’t fit too snugly, which can be uncomfortable. Ultimately, though, refer to the brand’s recommendation. Most have online chat options or will make a recommendation in their sizing chart.