Envelope dimensions API

Looks up an envelope size (ISO C series, DL, US No.10/No.9/A7/Monarch) returning mm/inch/pixel dimensions at a DPI and the paper-fold it accommodates. Answers 'What are DL envelope dimensions and what does it hold?', 'How many pixels is a C5 envelope at 300 DPI?'.

Price$0.02per request

MethodPOST

Route/v1/design/envelope-size

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

designprintenvelopedlc5no10dimensionsstationery

API URLhttps://x402.hexl.dev/v1/design/envelope-size

Integration docs

Example request

{
  "name": "DL",
  "dpi": 300
}

Example response

{
  "name": "DL",
  "dpi": 300,
  "mm": {
    "width": 110,
    "height": 220
  },
  "inches": {
    "width": 4.331,
    "height": 8.661
  },
  "pixels": {
    "width": 1299,
    "height": 2598
  },
  "holds": "A4 folded into thirds",
  "interpretation": "DL measures 110×220mm; A4 folded into thirds."
}

Input schema

{
  "type": "object",
  "required": [
    "name"
  ],
  "properties": {
    "name": {
      "type": "string",
      "description": "Envelope name",
      "examples": [
        "DL",
        "C5",
        "No10",
        "Monarch"
      ]
    },
    "dpi": {
      "type": "number",
      "description": "DPI for pixel output (default 300)",
      "examples": [
        300
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}