QTc Correction
Compute corrected QT interval using four published formulas - Bazett, Fridericia, Framingham, and Hodges - side by side.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- QT interval
- 400 ms
- Heart rate
- 60 bpm
Result: All four formulas ~400 ms
The tool opens with these values already filled in. Replace them with your own.
What you enter
- QT interval
- Heart rate
What this is
Bazett is the historical default; Fridericia is preferred at heart rates outside 60-100 bpm; Framingham and Hodges are linear alternatives that avoid Bazett's overcorrection at high rates. Enter a QT in milliseconds and a heart rate, and Sophie Well returns all four QTc values rounded to the nearest millisecond.
When to use it
Use this when reading an ECG and the machine-printed QTc looks suspect, when reviewing a patient on QT-prolonging medications, or when you want to compare formulas before documenting a single value. The result is reference math only; sustained QTc above 500 ms or any clinically driven QTc concern warrants direct ECG review and pharmacy or cardiology consult.
How this is calculated
Bazett 1920; Fridericia 1920 (reprinted in Ann Noninvasive Electrocardiol. 2003;8(4):343-351); Sagie (Framingham) Am J Cardiol. 1992;70:797-801; Hodges 1983. All four formulas reported side by side. Read the sources: Fridericia 1920 (reprint) ↗, Sagie 1992 ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.
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