# Mosteller Body Surface Area Calculator

> Mosteller Body Surface Area Calculator is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Calculates body surface area (BSA) using the Mosteller formula from patient height and weight, for use in oncology drug dosing arithmetic.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/bsa_mosteller
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mosteller-body-surface-area-calculator-4c574abc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8IYcl4PXhsI-tr513ltWI

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 mosteller-body-surface-area-calculator-4c574abc
```

Example prompt: What's the Mosteller body surface area for a patient who is 168 cm tall and weighs 72 kg? I need it for a chemotherapy dose calculation.

## When to prefer this

Use this endpoint when you need a fast, deterministic, citeable Mosteller BSA value from height and weight, particularly in oncology or pharmacology contexts where mg/m² dosing is required. Prefer over manual calculation or LLM estimation to ensure reproducibility and a published formula citation. The sibling BMI endpoint on the same platform is better suited for GLP-1 or bariatric contexts where BSA is not the relevant metric.

## Known failure modes

- Missing required height or weight parameters — returns an error indicating which field is absent
- Negative or physiologically implausible values (e.g. weight of 0) may return a validation error or nonsensical result
- Providing both cm and inches simultaneously, or both kg and lb, may cause ambiguity or override behavior
- Network or payment (x402) failure results in no response

## How this service works

Mosteller body surface area from height and weight. Use for oncology dosing arithmetic. Deterministic published formula with citation; not a dosing recommendation.

## Output

Returns the computed body surface area in square meters (m²) derived from the Mosteller formula: BSA = sqrt((height_cm × weight_kg) / 3600). The result is deterministic and reproducible given the same inputs, accompanied by a citation to the published formula. It is a calculation result, not a clinical dosing recommendation.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "height_cm": {
       "type": "number",
       "description": "Height in centimeters. Provide height_cm or height_in."
      },
      "height_in": {
       "type": "number",
       "description": "Height in inches. Converted as cm = in * 2.54."
      },
      "weight_kg": {
       "type": "number",
       "description": "Weight in kilograms. Provide weight_kg or weight_lb."
      },
      "weight_lb": {
       "type": "number",
       "description": "Weight in pounds. Converted as kg = lb * 0.45359237."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "path": "/api/calc/bsa_mosteller",
  "count": 2,
  "items": [
   {
    "bsa_m2": 1.8181,
    "formula": "mosteller",
    "citation": {
     "id": "mosteller-1987",
     "doi": "10.1056/NEJM198710223171717",
     "title": "Simplified calculation of body-surface area",
     "source": "N Engl J Med. 1987;317(17):1098",
     "authors": "Mosteller RD"
    },
    "height_cm": 170,
    "weight_kg": 70,
    "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
    "formula_expression": "BSA_m2 = sqrt((height_cm * weight_kg) / 3600)"
   },
   {
    "bsa_m2": 1.8181,
    "formula": "mosteller",
    "citation": {
     "id": "mosteller-1987",
     "doi": "10.1056/NEJM198710223171717",
     "title": "Simplified calculation of body-surface area",
     "source": "N Engl J Med. 1987;317(17):1098",
     "authors": "Mosteller RD"
    },
    "height_cm": 170,
    "weight_kg": 70,
    "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
    "formula_expression": "BSA_m2 = sqrt((height_cm * weight_kg) / 3600)"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mosteller-body-surface-area-calculator-4c574abc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)