Hat Size Calculator

Adjust the calculator values below

Recommended chart size L
Adult international size L
Child age guide Not used - adult chart
US hat size 7 3/8
UK hat size 7 1/4
Matched chart circumference 59 cm
Entered head circumference 59 cm
Equivalent circumference in centimeters 59 cm
Equivalent circumference in inches 23.228 in
Difference to matched chart row Exact match
Chart-matching method Next listed size when between rows
Chart range status Within the adult chart range
Fit note Exact chart-row match; confirm the brand-specific chart before buying
Measurement guidance Measure level around the widest part of the head, 1-2 cm above the ears
L
Recommended chart size Adult chart at 59 cm head circumference
Other Calculator

Hat Size Calculator

Convert adult or child head circumference to a recommended chart size, US hat size, UK hat size, and metric or imperial equivalents.

Measure head circumference at the hat line

Use a flexible tape around the most prominent part of the forehead and the furthest point at the back of the head, keeping it level about 1-2 centimeters (0.4-0.8 inch) above the ears. Keep the tape comfortably snug rather than pulling it tight, and repeat the measurement to catch placement errors.

Use the adult or child chart deliberately

The adult chart maps circumference to international XS-XXXL sizes plus US and UK numeric sizes. The child chart maps circumference to a broad age guide plus US and UK sizes. A child's age guide is approximate; measured circumference and the seller's own product chart are more useful than age alone.

Choose how to handle a measurement between chart rows

The default method selects the next listed circumference when the measurement falls between rows, following the source recommendation to choose the larger hat because a slightly roomy fit is usually easier to adjust. The optional nearest-row method is useful for comparison but can recommend a row smaller than the measured head.

Do not confuse numeric hat size with inches

A US or UK size such as 7 3/8 is a chart designation, not a 7 3/8-inch head circumference. US and UK numeric sizes are also not interchangeable: for the same circumference, the US size is usually one eighth larger than the UK size.

Confirm fit against the manufacturer chart

Hat charts are practical references rather than universal standards. Brand grading, crown shape, brim style, material stretch, liners, hairstyles, intended fit, and measurement technique can change the best size. If a measurement is outside the displayed chart, use a manufacturer-specific extended or custom-size chart.

Frequently asked questions

Common questions about measuring head circumference, adult and child charts, US and UK sizes, between-size choices, and brand-specific fit.

How do I measure my head for a hat?

Wrap a flexible tape level around the most prominent forehead and the furthest point at the back of the head, about 1-2 centimeters (0.4-0.8 inch) above the ears. Keep it comfortably snug and repeat the measurement.

What should I do if my head circumference is between sizes?

The default method chooses the next listed circumference, following the source recommendation to choose the larger size because a slightly roomy hat is generally easier to adjust. You can open the fit options to compare the nearest chart row.

Are US and UK hat sizes the same?

No. For the same circumference, the US numeric size is usually one eighth larger than the UK size. Use the result in the system printed by the manufacturer rather than treating the two labels as interchangeable.

Is a 7 3/8 hat for a 7 3/8-inch head?

No. A value such as 7 3/8 is a numeric hat-size designation, not head circumference in inches. A 59-centimeter adult head, about 23.2 inches, maps to US 7 3/8 and UK 7 1/4 in this chart.

How does the child hat-size chart work?

The child chart maps measured circumference to US and UK sizes plus a broad age guide. Age alone is not a reliable fit measurement, so use actual circumference and confirm it against the seller's chart.

Why might a brand recommend a different hat size?

Hat sizing is not perfectly universal. Brand grading, crown shape, material stretch, liners, hairstyle, intended fit, and tape placement can shift the best choice, so the product-specific chart should make the final decision.