ForHosting KIT · Developer Utilities

QTc Framingham Calculator

The QTc Framingham calculator corrects a measured QT interval for heart rate with the Framingham linear formula.

● BetaFree · in your browser

Use it from WebAPIEmailTelegramApp soon

Enter QT in milliseconds and heart rate in beats per minute to receive the RR interval and corrected QT in milliseconds. The calculation is fully offline, deterministic, and suitable for repeatable software workflows. It is an arithmetic aid, not a diagnosis, and clinical interpretation should account for the tracing, measurement method, patient context, and professional guidance.

How to use it

Enter your values in the form above. The tool checks them before calculating and shows the result on the same page.

Check your inputs

Use the labels and units shown next to each field. If something is missing or outside the allowed range, the page points to the field to fix.

Use it again or automate it

Use the browser tool for individual checks and the API when you need the same capability in an automated workflow.

What you can do with it

Get an answer now

Enter one set of values and see the result without building a spreadsheet or script.

Compare scenarios

Change one value at a time and rerun the calculation to understand what affects the result.

Automate repeated work

Use the API when the same calculation needs to run inside your product or workflow.

FAQ

What formula does this calculator use?

It uses QTc = QT + 154 × (1 − RR), where QT and QTc are in milliseconds and RR is 60 divided by heart rate in seconds.

Which units should I enter?

Enter QT in milliseconds and heart rate in beats per minute. The returned QTc is in milliseconds.

Does the result diagnose a prolonged QT interval?

No. The result is an arithmetic correction only. Interpretation requires the ECG and relevant clinical context.

What happens with invalid or non-positive values?

Missing, non-numeric, non-finite, zero, and negative inputs return an invalid_input error instead of a result.

What does the API request cost?

Each API request costs $0.002. The calculation is also available locally in the browser.

For developers — API access

Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.

API endpoint

POSThttps://api.kit.forhosting.com/health/qtc-framingham

Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.

Call it from your stack

curl -X POST https://api.kit.forhosting.com/health/qtc-framingham \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"qt_ms":400,"heart_rate_bpm":75}'

const res = await fetch("https://api.kit.forhosting.com/health/qtc-framingham", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "qt_ms": 400,
    "heart_rate_bpm": 75
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/health/qtc-framingham",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "qt_ms": 400,
    "heart_rate_bpm": 75
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/health/qtc-framingham", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"qt_ms":400,"heart_rate_bpm":75}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"qt_ms":400,"heart_rate_bpm":75}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/health/qtc-framingham", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)

Example request

{
  "qt_ms": 400,
  "heart_rate_bpm": 75
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "health.qtc_framingham",
  "status": "queued",
  "_links": {
    "result": "/tasks/tsk_…/result"
  }
}

The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.

Pricing

Per request$0.002

Published price — no tokens, no invented credits. A failed task is never charged.

Errors

HTTP	Code	Meaning
`401`	`unauthorized`	Missing or invalid API key.
`402`	`insufficient_balance`	Your balance doesn't cover the task price.
`404`	`unknown_type`	That task type doesn't exist.
`429`	`rate_limited`	Too many requests. Use the webhook instead of polling.

Read the full KIT documentation →