Apparel SizeHat Size

Head Circumference (in) to EU Size Hat Size for Standard Fit

Snapshot

22.5 Head Circumference (in) equals 57.2 EU Size.

  • Reference basis: This result uses the selected in mapping as the profile basis.
  • Example: For 21.5 Head Circumference (in), the in mapping returns 54.6 EU Size under the same fit assumptions.

Interactive conversion

Converter Calculator

Decimals: 1.5 or 1,5. Fractions: 1/2. Scientific notation: 1e3. Write 1000 without grouping separators.

57.2 EU Size value

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API and AI agent access

Head Circumference (in) to EU Size Hat Size for Standard Fit. fit: standard-fit.

Machine-readable identifiers

Conversion family
hat-size
Source unit
circumference-inches
Target unit
eu-size
Fit
standard-fit

Use these identifiers in the API request. Sources and model limits also apply to software clients.

Example API request and response

POST /api/v1/convert

Request

{
  "family": "hat-size",
  "value": 22.5,
  "from": "circumference-inches",
  "to": "eu-size",
  "parameters": {
    "fit": "standard-fit"
  }
}

Essential response

{
  "ok": true,
  "conversion": {
    "family": "hat-size",
    "value": 22.5,
    "from": "circumference-inches",
    "to": "eu-size",
    "result": {
      "raw": 57.15,
      "display": "57.2"
    },
    "canonicalPath": "/apparel-size/hat-size/circumference-inches-to-eu-size-for-standard-fit/"
  }
}
API, OpenAPI and WebMCP documentation

Explanation

Head Circumference (in) converts to EU Size using head circumference in millimeters. Fit profile: Standard Fit.

Model estimate based on head circumference, not a fit guarantee. No manufacturer chart is established for this model; compare your measurement with the brand’s chart.

Method & Size Mapping

  • Model basis: output depends on the selected fit profile and follows the same fit mapping in both directions.
  • Profile reference: in.
  • Consistency rule: calculator output and table values keep the same fit profile in both directions.

Common Conversion Values

Head Circumference (in) valueEU Size value
21 1/2 54.6
22 55.9
22 1/2 57.2
23 58.4
23 1/2 59.7