# Audio Calc: Bitrate & File Size Calculator

> Audio Calc: Bitrate & File Size Calculator is a paid API for AI agents from audio-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Calculates audio file size from bitrate and duration, solves for missing bitrate or duration given file size, and computes PCM file size from sample rate, bit depth, and channels.

## Facts

- Endpoint: GET https://audio-calc.x402tookit.com/bitrate-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/audio-calc-bitrate-file-size-calculator-be781721
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__dCOMBUGM_pklgkb6ctV8

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 audio-calc-bitrate-file-size-calculator-be781721
```

Example prompt: How big will a 45-minute podcast be if I encode it at 128 kbps? Also tell me how many megabytes per hour that works out to.

## When to prefer this

Use this endpoint when you need to compute audio file sizes, derive bitrate or duration from file size, or calculate raw PCM storage requirements — especially in agentic workflows involving podcast planning, audio streaming budget estimation, DAW session sizing, or storage capacity calculations. It handles both compressed (bitrate-based) and uncompressed (PCM) audio math in a single call.

## Known failure modes

- Insufficient query parameters provided to solve for any single unknown — returns null results with reasons array explaining what's missing
- Conflicting or zero-value inputs (e.g. zero duration) may yield null or degenerate results
- Missing required combination for PCM mode (sampleRate, bitDepth, and channels all needed together)
- Non-numeric or out-of-range values may cause schema validation errors

## How this service works

Audio file size from bitrate and duration, or the bitrate or duration it implies; PCM size from rate, depth and channels.

## Output

Returns file size in multiple units (bytes, KB, MB, GB, KiB, MiB, GiB), duration in seconds and minutes, bitrate in kbps, bytes per second, megabytes per hour, a human-readable summary, and a PCM flag indicating whether the calculation used PCM mode. For unsolvable inputs, returns null fields with reasons explaining what's missing.

## 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": [],
     "properties": {
      "seconds": {
       "type": "number",
       "description": "Duration in seconds"
      },
      "bitDepth": {
       "type": "integer",
       "description": "PCM bits per sample"
      },
      "channels": {
       "type": "integer",
       "description": "Number of channels (default 2)"
      },
      "sizeBytes": {
       "type": "number",
       "description": "File size in bytes (to solve for bitrate or duration)"
      },
      "sampleRate": {
       "type": "number",
       "description": "PCM sample rate in Hz (with bitDepth and channels)"
      },
      "bitrateKbps": {
       "type": "number",
       "description": "Compressed bitrate in kilobits per second (1 kbps = 1000 bits/s)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "pcm": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "sizeGB": {
       "type": [
        "null",
        "number"
       ]
      },
      "sizeKB": {
       "type": [
        "null",
        "number"
       ]
      },
      "sizeMB": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "minutes": {
       "type": [
        "null",
        "number"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "seconds": {
       "type": [
        "null",
        "number"
       ]
      },
      "sizeGiB": {
       "type": [
        "null",
        "number"
       ]
      },
      "sizeKiB": {
       "type": [
        "null",
        "number"
       ]
      },
      "sizeMiB": {
       "type": [
        "null",
        "number"
       ]

… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/audio-calc-bitrate-file-size-calculator-be781721/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from audio-calc.x402tookit.com](https://www.zero.xyz/host/audio-calc.x402tookit.com/llms.txt)