QTc Suite (Bazett / Fridericia / Framingham / Hodges)
QTc Suite (Bazett / Fridericia / Framingham / Hodges) - a deterministic tool in Sophie Well's Clinical Math & Conversions group.
Open the QTc Suite (Bazett / Fridericia / Framingham / Hodges) → Runs in your browser. No signup, no tracking.
What this is
Compute corrected QT interval using four published formulas - Bazett, Fridericia, Framingham, and Hodges - side by side. 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. Sophie Well takes a raw QT in milliseconds and a heart rate and returns all four QTc values, with sex-specific thresholds for prolongation flagged in the result.
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 (azithromycin, ondansetron, methadone, antipsychotics, fluoroquinolones), or when comparing the formulas before documenting a single value. A QTc above 500 ms or a relative increase of more than 60 ms from baseline raises serious arrhythmia risk and warrants pharmacy or cardiology consult - the suite gets you to the comparison fast, but the action item is still clinical.
References
Bazett 1920; Fridericia 1920; Sagie (Framingham) 1992; Hodges 1983.
Worked example: All four formulas ~400 ms
Sophie Well is a reference and educational tool. Not medical, legal, or financial advice. Does not replace clinician judgment, professional billing review, or legal counsel.