# Publishing Calc: Full Paperback Cover Size Calculator

> Publishing Calc: Full Paperback Cover Size Calculator is a paid API for AI agents from publishing-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Calculates full paperback cover width and height (with bleed) from trim size and page count, returning dimensions in inches, mm, and pixels.

## Facts

- Endpoint: GET https://publishing-calc.x402tookit.com/cover-size?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/publishing-calc-full-paperback-cover-size-calculator-d80ef46a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KIZa_5nQDIrYDN7DUqsTI

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability publishing-calc-full-paperback-cover-size-calculator-d80ef46a
```

Example prompt: What's the full paperback cover size for a 6x9 trim, 320-page book on white paper with standard 0.125-inch bleed? Give me the dimensions in inches, mm, and pixels at 300 DPI.

## When to prefer this

Use this endpoint when you need the complete, print-ready wraparound cover dimensions for a paperback book — accounting for spine thickness, bleed, and output in multiple unit systems. It is purpose-built for self-publishing and print-on-demand workflows (KDP, IngramSpark, etc.) and handles paper-type-specific spine calculations automatically. Prefer it over manual calculation or general-purpose math tools when you need reliable, publisher-standard dimensions in inches, mm, and pixels simultaneously.

## Known failure modes

- Missing required query parameters (trimWidth, trimHeight, pages) return a validation error
- Non-integer page count or negative values may cause computation errors
- Invalid unit value (not 'in' or 'mm') may fall back to default
- Invalid paper type string falls back to white paper defaults
- Very low page counts may produce unusually thin spine widths
- Payment failure (x402) prevents the call from completing

## How this service works

Full paperback cover width and height with bleed from trim size and page count, in inches, mm and pixels.

## Output

Returns the full cover width and height (spanning front, spine, and back) in inches, millimeters, and pixels, along with the spine width in inches, the bleed value used, and the DPI setting applied. Also includes a summary string and any disclaimers or degraded-mode flags.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "trimWidth",
      "trimHeight",
      "pages"
     ],
     "properties": {
      "dpi": {
       "type": "number",
       "description": "Pixels per inch for the pixel size (default 300)"
      },
      "unit": {
       "type": "string",
       "description": "in (default) or mm for trim and bleed"
      },
      "bleed": {
       "type": "number",
       "description": "Bleed on each outer edge in the same unit (default 0.125 in or 3.175 mm)"
      },
      "pages": {
       "type": "integer",
       "description": "Total printed page count"
      },
      "paper": {
       "type": "string",
       "description": "white (default), cream or color; sets spine thickness"
      },
      "trimWidth": {
       "type": "number",
       "description": "Trim width of one page (inches by default)"
      },
      "trimHeight": {
       "type": "number",
       "description": "Trim height of one page"
      },
      "pageThicknessIn": {
       "type": "number",
       "description": "Override: inches of spine per page"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "bleedIn": {
       "type": [
        "null",
        "number"
       ]
      },
      "dpiUsed": {
       "type": [
        "null",
        "number"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "inputUnit": {
       "t
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/publishing-calc-full-paperback-cover-size-calculator-d80ef46a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from publishing-calc.x402tookit.com](https://www.zero.xyz/host/publishing-calc.x402tookit.com/llms.txt)