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Sizing tool

Hat Size Calculator

Enter head circumference and find the nearest fitted and letter-size reference.

Find a hat size

Enter head circumference to find the nearest chart row.
Diagram showing head circumference measured around the position where a hat will sit.
Measure around the intended wearing position first, then use the nearest fitted or letter-size reference.

What the calculator is doing

The calculator finds the nearest circumference row and returns the nearby fitted and letter-size references. It does not attempt to model crown shape or material stretch.

Use the result as the size to inspect first, then follow the manufacturer’s advice if your measurement sits between rows.

Method & references

How this guidance is checked

These sources support the measurement method and help check real-world variation. They are not presented as one universal brand-size table.

  • New Era Fitted Caps Size Chart — New Era. Fitted-cap circumference cross-check and evidence that label CM values can differ from measured head circumference.
  • Men Size Guide — H&M. Cross-check for men’s EU/US clothing, chest and waist ranges, trousers, jackets, and suit-style numeric references.

Related sizing tasks

Hat Size ChartHow to Measure Hat Size

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