# Units and Conversions – Physical Unit Converter

> Units and Conversions – Physical Unit Converter is a paid API for AI agents from units-convert.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-21).

Converts a numeric value from one physical unit to another across length, mass, volume, area, speed, pressure, energy, power, time, and temperature.

## Facts

- Endpoint: GET https://units-convert.x402tookit.com/unit-convert?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/units-and-conversions-physical-unit-converter-663c5781
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_PVkPAeoZxINb6kKLizaVY

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 units-and-conversions-physical-unit-converter-663c5781
```

Example prompt: Can you convert 26.2 miles to kilometers for me?

## When to prefer this

Use this endpoint when you need exact, deterministic physical unit conversions across standard measurement categories (length, mass, volume, area, speed, pressure, energy, power, time, temperature). Prefer it over general-purpose LLM math when precision and structured output (rounded result, category label, summary) are required. Not suited for cooking-specific measures (use the cooking converter sibling), data sizes, fuel economy, or Roman numeral conversions — those have dedicated sibling endpoints.

## Known failure modes

- Incompatible units (e.g. converting length to mass) returns an error or null result
- Unrecognized unit abbreviation causes a failed lookup
- Missing required query parameters (value, from, to) results in a 400-level error
- Payment not attached or insufficient USDC balance causes a 402 payment required response

## How this service works

Convert a value between units of length, mass, volume, area, speed, pressure, energy, power, time or temperature, exactly.

## Output

Returns the converted numeric result along with a rounded version, the source and target unit labels, the measurement category (e.g. length, temperature), a human-readable summary, and optional disclaimer or degraded-quality 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": [
      "value",
      "from",
      "to"
     ],
     "properties": {
      "to": {
       "type": "string",
       "description": "Target unit of the same kind"
      },
      "from": {
       "type": "string",
       "description": "Unit, e.g. mi, km, lb, kg, gal_us, c, f, psi, kwh"
      },
      "value": {
       "type": "number",
       "description": "The number to convert"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "to": {
       "type": [
        "null",
        "string"
       ]
      },
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "from": {
       "type": [
        "null",
        "string"
       ]
      },
      "input": {
       "type": [
        "null",
        "number"
       ]
      },
      "result": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "category": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "resultRounded": {
       "type": [
        "null",
        "number"
       ]
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/units-and-conversions-physical-unit-converter-663c5781/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from units-convert.x402tookit.com](https://www.zero.xyz/host/units-convert.x402tookit.com/llms.txt)