# Nadler 1962 Blood Volume Estimator

> Nadler 1962 Blood Volume Estimator 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).

Estimates total blood volume in liters for adults using the Nadler 1962 equations, given sex, height, and weight

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/nadler
- 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/nadler-1962-blood-volume-estimator-fbf9e5b4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6qPSF88C-fdcTl1LS5kW_

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 nadler-1962-blood-volume-estimator-fbf9e5b4
```

Example prompt: Use the Nadler 1962 equation to estimate blood volume for a male patient who is 178 cm tall and weighs 82 kg.

## When to prefer this

Use this endpoint when you need the specific Nadler 1962 published equations for adult blood volume estimation from height, weight, and sex — particularly when citeable, deterministic arithmetic is required. Prefer this over the 70 mL/kg rule of thumb when individualized anthropometric data is available. Not appropriate for pediatric patients, for whom age-adjusted formulas are needed, nor as a substitute for direct blood volume measurement.

## Known failure modes

- Missing required 'sex' parameter returns an error
- Neither height_cm/height_in nor weight_kg/weight_lb provided causes a validation error
- Invalid sex value (not 'male' or 'female') returns an enum validation error
- Extreme anthropometric values outside the original study's adult range may produce biologically implausible outputs without a warning
- Payment not included or insufficient USDC results in 402 payment required response

## How this service works

Nadler 1962 predicted blood volume in liters from height, weight, and sex (separate male and female equations). Deterministic published arithmetic with citation. For adults as published; this tool does not take age. Not a transfusion order, Lemmens–Bernstein–Brodsky estimate, or 70 mL/kg rule of thumb.

## Output

A numeric estimate of total blood volume in liters computed via the sex-specific Nadler 1962 regression equations, based on the provided height and weight inputs. No age adjustment is applied. Result is deterministic given the same inputs.

## 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": [
      "sex"
     ],
     "properties": {
      "sex": {
       "enum": [
        "female",
        "male"
       ],
       "type": "string",
       "description": "Sex used by Nadler 1962 (separate male and female equations)."
      },
      "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/nadler",
  "count": 2,
  "items": [
   {
    "sex": "male",
    "formula": "nadler",
    "citation": {
     "id": "nadler-1962",
     "pmid": "21936146",
     "title": "Prediction of blood volume in normal human adults",
     "source": "Surgery. 1962;51(2):224-232",
     "authors": "Nadler SB, Hidalgo JH, Bloch T"
    },
    "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.",
    "blood_volume_l": 4.66,
    "blood_volume_ml": 4660,
    "formula_expression": "BV_L = 0.3669 * H^3 + 0.03219 * W + 0.6041 (male); BV_L = 0.3561 * H^3 + 0.03308 * W + 0.1833 (female); H meters, W kg"
   },
   {
    "sex": "male",
    "formula": "nadler",
    "citation": {
     "id": "nadler-1962",
     "pmid": "21936146",
     "title": "Prediction of blood volume in normal human adults",
     "source": "Surgery. 1962;51(2):224-232",
     "authors": "Nadler SB, Hidalgo JH, Bloch T"
    },
    "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.",
    "blood_volume_l": 4.66,
    "blood_volume_ml": 4660,
    "formula_expression": "BV_L = 0.3669 * H^3 + 0.03219 * W + 0.6041 (male); BV_L = 0.3561 * H^3 + 0.03308 * W + 0.1833 (female); H meters, W kg"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nadler-1962-blood-volume-estimator-fbf9e5b4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
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