Calc Nadler
by magent in Other
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.
https://api.magentlab.com/api/calc/nadler- Price
- $0.007
- per call in USDC
- Uptime
- 97.0%
- last 30 days
- Response time
- 151 ms
- 353 ms slowest 5%
- Last check
- Failed
- 4 h ago, next any minute now
Reliability
Latest check failed 4 h ago: Timed out
Status and outage history · Atom feed · Watch with other listings
How to call it
POST https://api.magentlab.com/api/calc/nadler
Each call costs $0.007 in USDC on Base, paid with the request over x402.
Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.
Example request
From the listing.
POST https://api.magentlab.com/api/calc/nadler
content-type: application/json
{
"items": [
{
"height_cm": 170,
"height_in": 66.92913385826772,
"sex": "male",
"weight_kg": 70,
"weight_lb": 154.3236
},
{
"height_cm": 170,
"height_in": 66.92913385826772,
"sex": "male",
"weight_kg": 70,
"weight_lb": 154.3236
}
]
}Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
items | array of object | Yes |
Example response
The provider's example. We can't check it without paying.
Example response, 40 lines
{
"count": 2,
"items": [
{
"blood_volume_l": 4.66,
"blood_volume_ml": 4660,
"citation": {
"authors": "Nadler SB, Hidalgo JH, Bloch T",
"id": "nadler-1962",
"pmid": "21936146",
"source": "Surgery. 1962;51(2):224-232",
"title": "Prediction of blood volume in normal human adults"
},
"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": "nadler",
"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",
"height_cm": 170,
"sex": "male",
"weight_kg": 70
},
{
"blood_volume_l": 4.66,
"blood_volume_ml": 4660,
"citation": {
"authors": "Nadler SB, Hidalgo JH, Bloch T",
"id": "nadler-1962",
"pmid": "21936146",
"source": "Surgery. 1962;51(2):224-232",
"title": "Prediction of blood volume in normal human adults"
},
"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": "nadler",
"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",
"height_cm": 170,
"sex": "male",
"weight_kg": 70
}
],
"path": "/api/calc/nadler"
}Call it from code
The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.007.
curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.magentlab.com/api/calc/nadler' \
-H 'content-type: application/json' \
--data-raw '{"items":[{"height_cm":170,"height_in":66.92913385826772,"sex":"male","weight_kg":70,"weight_lb":154.3236},{"height_cm":170,"height_in":66.92913385826772,"sex":"male","weight_kg":70,"weight_lb":154.3236}]}'
# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - -X POST 'https://api.magentlab.com/api/calc/nadler' \
-H 'content-type: application/json' \
--data-raw '{"items":[{"height_cm":170,"height_in":66.92913385826772,"sex":"male","weight_kg":70,"weight_lb":154.3236},{"height_cm":170,"height_in":66.92913385826772,"sex":"male","weight_kg":70,"weight_lb":154.3236}]}' \
| grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decodeJavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";
// Pays at most $0.007 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.007" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);
// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.007 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.magentlab.com%2Fapi%2Fcalc%2Fnadler&method=POST
const res = await pay("https://api.magentlab.com/api/calc/nadler", {
method: "POST",
headers: { "content-type": "application/json" },
body: JSON.stringify({
"items": [
{
"height_cm": 170,
"height_in": 66.92913385826772,
"sex": "male",
"weight_kg": 70,
"weight_lb": 154.3236
},
{
"height_cm": 170,
"height_in": 66.92913385826772,
"sex": "male",
"weight_kg": 70,
"weight_lb": 154.3236
}
]
}),
});
console.log(res.status, await res.text());Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client
# Pays at most $0.007 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.007"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))
with x402_requests(client) as session:
res = session.post(
"https://api.magentlab.com/api/calc/nadler",
json={
"items": [
{
"height_cm": 170,
"height_in": 66.92913385826772,
"sex": "male",
"weight_kg": 70,
"weight_lb": 154.3236,
},
{
"height_cm": 170,
"height_in": 66.92913385826772,
"sex": "male",
"weight_kg": 70,
"weight_lb": 154.3236,
},
],
},
)
print(res.status_code, res.text)Security scan
1 finding
- Charges more than its listed price in payment
Listed at $0.005, charges $0.007
Recent checks
| When | Result | HTTP | Time | Price |
|---|---|---|---|---|
| 4 h ago | Timed out | - | - | - |
| 9 h ago | Passed | 402 | 162 ms | $0.007 |
| 14 h ago | Passed | 402 | 144 ms | $0.007 |
| 18 h ago | Passed | 402 | 345 ms | $0.007 |
| 23 h ago | Passed | 402 | 148 ms | $0.007 |
Show 10 older checks
| 28 h ago | Passed | 402 | 168 ms | $0.007 |
| 32 h ago | Passed | 402 | 155 ms | $0.007 |
| 36 h ago | Passed | 402 | 1.7 s | $0.007 |
| 40 h ago | Passed | 402 | 225 ms | $0.007 |
| 45 h ago | Passed | 402 | 165 ms | $0.007 |
| 2 days ago | Passed | 402 | 312 ms | $0.007 |
| 2 days ago | Passed | 402 | 161 ms | $0.007 |
| 2 days ago | Passed | 402 | 142 ms | $0.007 |
| 3 days ago | Passed | 402 | 151 ms | $0.007 |
| 3 days ago | Passed | 402 | 256 ms | $0.007 |
History
| 11 Oct 2026 | Price changed from $0.005 to $0.007 |