# Publishing Calc – Ebook File Size Estimator

> Publishing Calc – Ebook File Size Estimator is a paid API for AI agents from publishing-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-30).

Estimates ebook file size in KB and MB from word count, image count, average image size, and adjustable compression/overhead parameters.

## Facts

- Endpoint: GET https://publishing-calc.x402tookit.com/ebook-size?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/publishing-calc-ebook-file-size-estimator-5d6a1bd8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xRXCP2OYzdCc-roofZ3Ba

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-ebook-file-size-estimator-5d6a1bd8
```

Example prompt: How big will my ebook be if it's 75000 words with 15 images averaging 150 KB each? Give me the estimated file size in KB and MB.

## When to prefer this

Use this endpoint when you need a fast, parameterized estimate of an ebook's file size before publishing, uploading, or pricing — especially when you want to model the impact of image count, image size, or compression settings without building your own formula. Ideal for self-publishing workflows, KDP upload planning, or publishing calculators that need a breakdown of text vs. image size contributions.

## Known failure modes

- Missing required 'words' query parameter returns an error
- Non-numeric values for numeric fields cause validation errors
- Extreme compression ratios outside 0.1–1 may produce unexpected results
- Very large word or image counts may produce unrealistic estimates if inputs are misconfigured

## How this service works

Estimate ebook file size in KB and MB from word count, image count and average image size (all adjustable).

## Output

Returns a structured object with the estimated total ebook file size in KB and MB, a breakdown of compressed text KB, images KB, overhead KB, raw text KB, the percentage of file size from images, the parameters used (bytesPerWord, textCompression), a human-readable summary and verdict, plus optional disclaimer and reasons fields.

## 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": [
      "words"
     ],
     "properties": {
      "words": {
       "type": "number",
       "description": "Word count of the book"
      },
      "images": {
       "type": "integer",
       "description": "Number of embedded images (default 0)"
      },
      "avgImageKb": {
       "type": "number",
       "description": "Average size of one embedded image in KB, 1 KB = 1000 bytes (default 200)"
      },
      "overheadKb": {
       "type": "number",
       "description": "Fixed overhead in KB for stylesheet, metadata and navigation (default 50)"
      },
      "bytesPerWord": {
       "type": "number",
       "description": "Uncompressed text bytes per word incl. markup (default 6.5)"
      },
      "textCompression": {
       "type": "number",
       "description": "Zip size as a fraction of raw text, 0.1 to 1 (default 0.4)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "words": {
       "type": [
        "null",
        "number"
       ]
      },
      "images": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "totalKb": {
       "type": [
        "null",
        "number"
       ]
      },
      "totalMb": {
       "type": [
        "null",
        "number"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "imagesKb": {
       "type": [
        "nul
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/publishing-calc-ebook-file-size-estimator-5d6a1bd8/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)