MAGENT

Body size · LIVE

Devine ideal body weight

Devine IBW

Compute Devine ideal body weight and 0.4 adjusted body weight from height, sex, and actual weight.

LIVE $0.005 USDC GET /api/calc/ibw_devine

Markdown: /docs/ibw.md · Canonical: https://magentlab.com/docs/ibw

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Compute Devine ideal body weight and 0.4 adjusted body weight from height, sex, and actual weight.

When to use

When a label or protocol still cites Devine IBW or 0.4 AdjBW and an agent must not invent the kilograms.

When not to use

  • Not a dosing recommendation. magent does not apply IBW to Cockcroft–Gault unless you call CrCl separately with that weight.
  • Devine is undefined below 60 inches in the original table; this implementation still evaluates the linear formula.

Formula

IBW_kg = 50 (male) or 45.5 (female) + 2.3 * (height_in - 60); AdjBW_kg = IBW_kg + 0.4 * (TBW_kg - IBW_kg) when TBW > IBW, else TBW_kg

Citation

Title
Gentamicin therapy
Authors
Devine BJ
Source
Drug Intell Clin Pharm. 1974;8:650-655
DOI
none

Worked example

70 in male, 90 kg

Given: height_in=70sex=maleweight_kg=90

  1. IBW = 50 + 2.3 * (70 - 60) = 73.0 kg
  2. TBW 90 > IBW 73, so AdjBW = 73 + 0.4 * (90 - 73) = 79.8 kg

Also searched as

  • Devine IBW
  • adjusted body weight 0.4
  • ideal body weight
  • AdjBW

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/ibw_devine?height_in=70&sex=male&weight_kg=90

Full URL: https://api.magentlab.com/api/calc/ibw_devine?height_in=70&sex=male&weight_kg=90

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/ibw_devine?height_in=70&sex=male&weight_kg=90"

Parameters

Name Type Required Description
height_cm number optional Height in centimeters. Provide height_cm or height_in.
height_in number optional Height in inches. Devine uses inches: IBW adds 2.3 kg per inch over 60.
sex string required · female, male Sex used by Devine (50 kg male, 45.5 kg female base).
weight_kg number optional Actual total body weight in kilograms. Provide weight_kg or weight_lb.
weight_lb number optional Actual total body weight in pounds.

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/ibw_devine Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

  • 1 to 25 items. Each item uses the same keys as the GET query parameters.
  • POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
  • The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
  • HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
  • Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
  • x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "height_in": "70",
      "sex": "male",
      "weight_kg": "90"
    },
    {
      "height_in": "70",
      "sex": "male",
      "weight_kg": "90"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/ibw_devine",
  "items": [
    {
      "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.",
      "citation": {
        "authors": "Devine BJ",
        "doi": null,
        "id": "devine-1974",
        "source": "Drug Intell Clin Pharm. 1974;8:650-655",
        "title": "Gentamicin therapy"
      },
      "formula": "devine_ibw_adjbw",
      "formula_expression": "IBW_kg = 50 (male) or 45.5 (female) + 2.3 * (height_in - 60); AdjBW_kg = IBW_kg + 0.4 * (TBW_kg - IBW_kg) when TBW > IBW, else TBW_kg",
      "sex": "male",
      "height_cm": 177.8,
      "actual_weight_kg": 90.0,
      "adjbw_factor": 0.4,
      "adjbw_kg": 79.8,
      "height_in": 70.0,
      "ibw_kg": 73.0
    },
    {
      "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.",
      "citation": {
        "authors": "Devine BJ",
        "doi": null,
        "id": "devine-1974",
        "source": "Drug Intell Clin Pharm. 1974;8:650-655",
        "title": "Gentamicin therapy"
      },
      "formula": "devine_ibw_adjbw",
      "formula_expression": "IBW_kg = 50 (male) or 45.5 (female) + 2.3 * (height_in - 60); AdjBW_kg = IBW_kg + 0.4 * (TBW_kg - IBW_kg) when TBW > IBW, else TBW_kg",
      "sex": "male",
      "height_cm": 177.8,
      "actual_weight_kg": 90.0,
      "adjbw_factor": 0.4,
      "adjbw_kg": 79.8,
      "height_in": 70.0,
      "ibw_kg": 73.0
    }
  ]
}

Response

Field Type Description
formula string devine_ibw_adjbw
formula_expression string Exact expressions used
sex string female or male
height_cm number Normalized height in cm
height_in number Height in inches used by Devine
actual_weight_kg number Total body weight in kg
ibw_kg number Devine ideal body weight, 1 decimal
adjbw_kg number Adjusted body weight with 0.4 factor when TBW > IBW, else TBW
adjbw_factor number Always 0.4
citation object Devine 1974 citation
disclaimer string Not-a-device notice

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "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.",
  "citation": {
    "authors": "Devine BJ",
    "doi": null,
    "id": "devine-1974",
    "source": "Drug Intell Clin Pharm. 1974;8:650-655",
    "title": "Gentamicin therapy"
  },
  "formula": "devine_ibw_adjbw",
  "formula_expression": "IBW_kg = 50 (male) or 45.5 (female) + 2.3 * (height_in - 60); AdjBW_kg = IBW_kg + 0.4 * (TBW_kg - IBW_kg) when TBW > IBW, else TBW_kg",
  "sex": "male",
  "height_cm": 177.8,
  "actual_weight_kg": 90.0,
  "adjbw_factor": 0.4,
  "adjbw_kg": 79.8,
  "height_in": 70.0,
  "ibw_kg": 73.0
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

HTTP Code When
400 invalid_height height_cm (50-250) or height_in (20-98) is required Returned before settlement; you are not charged.
400 invalid_sex sex must be female or male Returned before settlement; you are not charged.
400 invalid_weight weight_kg (1-500) or weight_lb (2-1100) is required Returned before settlement; you are not charged.
400 invalid_items POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400 invalid_item_count items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400 invalid_item each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

  • BMI — Compute Keys/Quetelet body-mass index from height and weight, plus a WHO adult band.
  • Mosteller BSA — Agents must not invent BSA from model memory. This endpoint computes published Mosteller body surface area in m^2 from height and weight; pay per request with x402 USDC on Base.
  • Cockcroft–Gault CrCl — Agents must not invent CrCl from model memory. This endpoint computes published Cockcroft–Gault creatinine clearance in mL/min using total body weight; pay per request with x402 USDC on Base.
  • Harris-Benedict BEE — Compute Harris–Benedict 1919 basal energy expenditure in kcal/day from height, weight, age, and sex.

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

  • HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON.
  • exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
  • HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
  • Execution is timeout-bounded and concurrency-capped.
  • Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.