Paper-size dimensions & DPI pixels API

Resolve a paper name (A4, Letter, Legal, B5, ...) to dimensions in mm, inches, and pixels at a chosen DPI, plus aspect ratio and series neighbors — accurate ISO 216 A/B/C and US sizes. The DPI→pixel derivation is the value-add for print/layout work. Answers 'what is A4 in pixels at 300 DPI', 'Letter size in mm', 'dimensions of A3', 'A4 vs Letter'.

Price$0.01per request

MethodPOST

Route/v1/ref/paper-size

StatusLive

MIME typeapplication/json

Rate limit60/minute

CacheNo cache

refpaper-sizeiso-216a4letterdpiprintdimensions

API URLhttps://x402.hexl.dev/v1/ref/paper-size

Integration docs

Example request

{
  "name": "A4",
  "dpi": 300
}

Example response

{
  "name": "A4",
  "found": true,
  "series": "A",
  "dpi": 300,
  "mm": {
    "width": 210,
    "height": 297
  },
  "inches": {
    "width": 8.27,
    "height": 11.69
  },
  "pixels": {
    "width": 2480,
    "height": 3508
  },
  "aspectRatio": 1.4143,
  "seriesNeighbors": [
    "A0",
    "A1",
    "A2",
    "A3",
    "A5",
    "A6",
    "A7",
    "A8"
  ],
  "index": 4
}

Input schema

{
  "type": "object",
  "required": [
    "name"
  ],
  "properties": {
    "name": {
      "type": "string",
      "examples": [
        "A4",
        "Letter"
      ]
    },
    "dpi": {
      "type": "number",
      "examples": [
        300
      ]
    }
  }
}

Output schema

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