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Health Calculators

QTc Calculator (Bazett)

Verified formula Updated Jun 2026 Private — runs on your device

Enter details
ms
bpm
Verified formula Private

Corrected QT (QTc)

400

For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.

How to use the QTc Calculator (Bazett)

The QTc Calculator (Bazett) works out your corrected qt (qtc) in an instant. Enter measured qt interval and heart rate and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.

  1. Enter the measured qt interval.
  2. Enter the heart rate.
  3. Read off your corrected qt (qtc) — the calculator updates automatically, with no button to press.

Formula

The QTc Calculator (Bazett) uses the formula:

Corrected QT (QTc) = Measured QT interval ÷ √(60 ÷ Heart rate)

Worked example

For example, with measured qt interval of 400 ms and heart rate of 60 bpm, the corrected qt (qtc) is 400.

Inputs used
Measured QT interval 400 ms
Heart rate 60 bpm
Results
Corrected QT (QTc) 400

Results are estimates for educational use, not professional advice.

Frequently asked questions

QTc is the QT interval corrected for heart rate, so it can be compared fairly across different rates.

QTc = QT ÷ √(RR), where RR is the interval between beats in seconds, found as 60 divided by heart rate.

Roughly above 450 ms in men and 470 ms in women is often considered prolonged, but interpretation needs clinical context.

Yes, including Fridericia and Framingham. Bazett is the most common but can over-correct at very high or low rates.

Enter the measured qt interval. Enter the heart rate. Read off your corrected qt (qtc) — the calculator updates automatically, with no button to press.

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