Hat Size Chart

The general hat size chart

Use this chart as a starting point, not as a promise from any hat maker. Each row shows a fitted US size, the head circumference in inches and cm that usually fits it, and the letter size that goes with it. The chart covers the common adult range, from 52 cm at the small end to 64 cm at the large end, and most adults fall somewhere in the middle of it.

Measure your head first, then look at the chart, rather than starting from a size you remember. Head size changes slowly over time, and a number from years ago may no longer match. A fresh measurement keeps the chart honest and stops you ordering the same wrong size twice.

Chart table

The table above lists fitted US sizes from 6 1/2 to 8, with head circumference in inches and cm and the matching letter size. Read the circumference columns as the head size that fits each row, because the hat itself is made slightly larger than the head so it can sit comfortably. These are broad general ranges, and each maker grades its own sizes, so always check the brand chart for the hat you are buying.

How to read the chart when your head falls between rows

Most people find that their head circumference falls neatly inside one row, but some fall on the boundary between two rows. When that happens, think about your hair first. Thick hair or hair worn up under the hat takes up room inside the crown, so a boundary measurement with thick hair usually does better in the larger row.

Hat style matters too. A firm structured hat has little give, so a boundary head in a firm hat is safer in the larger row. A soft hat that relaxes with wear, such as a beanie, can work in the smaller row. If you are choosing between two rows, lean toward the larger row when the hat is firm and toward the smaller row when it is soft, and check the return policy before you commit.

US fitted sizes and letter sizes in the chart

Fitted US sizes in the chart run from 6 1/2 to 8 in eighth size steps, and each step adds about half a cm to the head circumference. Letter sizes run from XS to XXL, and each letter covers two or three fitted sizes, so a letter size is a rougher guide than a fitted number. A hat sold only in letter sizes will fit a range of heads, which is why it often comes with an adjustable band or a stretch fit.

The letter column is most useful when you are buying a cap or a beanie, because those styles are usually sold in letter sizes. A fitted hat, such as a fedora or a cowboy hat, is usually sold by its fitted number, and the letter is only a rough cross reference. When both are printed, trust the fitted number and the cm column over the letter.

What the chart cannot tell you

The chart also cannot tell you how a hat will feel after hours on your head, since crown shape, band stiffness and hair volume all shape comfort. Two hats in the same chart row can feel different if one has a round crown and the other has a long oval crown. Keep the chart as a map for size, and let the style, the shape and the band guide the rest of the choice.

If you want a starting size worked out from your own measurement, use the hat size calculator and compare its result with the chart here. The calculator adds style and hair volume to the same circumference number, so it can point you to a different row from the chart when your hair is thick or the style is firm.