Bmi

{
  "asOf": "2026-10-11T08:36:49.046Z",
  "bmi": 22.857,
  "category": "Normal weight",
  "degraded": false,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "healthyWeightRangeKg": {
    "max": 76.26,
    "min": 56.66
  },
  "healthyWeightRangeLb": {
    "max": 168.1,
    "min": 124.9
  },
  "heightCm": 175,
  "kgToReachNormalMax": null,
  "kgToReachNormalMin": null,
  "notChecked": [
    "muscle mass, bone density, fat distribution and ethnicity: BMI cannot tell fat from muscle and the cutoffs are population screens, not diagnoses",
    "children and teens (they need age-and-sex growth percentiles)",
    "…2 more"
  ],
  "reasons": [
    "WHO adult categories: under 18.5 underweight, 18.5 to 24.9 normal, 25 to 29.9 overweight, 30 and over obese.",
    "BMI is a screening number, not a diagnosis: it ignores muscle, age, sex and body shape.",
    "…1 more"
  ],
  "source": "computed locally",
  "summary": "BMI 22.9: Normal weight. A BMI of 18.5 to 24.9 at 175 cm is 56.7 kg to 76.3 kg.",
  "verdict": "NORMAL_WEIGHT",
  "weightKg": 70
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://fitness-calc.x402tookit.com/bmi?height=175&weight=70'

# 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 - 'https://fitness-calc.x402tookit.com/bmi?height=175&weight=70' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// 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 $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
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 $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Ffitness-calc.x402tookit.com%2Fbmi
const res = await pay("https://fitness-calc.x402tookit.com/bmi?height=175&weight=70");
console.log(res.status, await res.text());

# 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 $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://fitness-calc.x402tookit.com/bmi?height=175&weight=70")
    print(res.status_code, res.text)