Quick guide
How to use this calculator
- Use the labels and unit notes to enter the requested measurement, date, time, or observation exactly as recorded.
- Check the visible method, population, and unit basis before using the result; switch modes rather than converting values mentally.
- Read the calculation audit and limitations together. The result supports measurement or tracking and does not replace diagnosis, treatment, or urgent medical assessment.
Calculation method
How the corrected qt (qtc) calculator works
Bazett: QT/√RR; Fridericia: QT/∛RR; Framingham: QT + 154(1−RR); Hodges: QT + 1.75(HR−60).
The result describes only the entered observations. It does not classify cardiovascular health, diagnose a condition, predict an event, or recommend treatment.
Worked example
Corrected QT (QTc) example
QT 400 ms at 60 beats/min gives QTc 400 ms with all four included formulas.
Bazett: QT/√RR; Fridericia: QT/∛RR; Framingham: QT + 154(1−RR); Hodges: QT + 1.75(HR−60).
Supported inputs
Precision and limits
Supported purpose
This route accepts QT 200–800 ms and heart rate 40–180 beats/min to prevent nonsensical extrapolation; those bounds are not normal/safe thresholds. Formula bias grows at rate extremes. Rhythm, QT measurement, QRS duration, medicines, electrolytes, age, sex, symptoms, and clinical context require professional interpretation; no dangerous-QT threshold is supplied.
Measurement quality
The output is only as reliable as the entered measurement, device, timing, units, and applicable reference population. Recheck unexpected values against the original record.
Clinical boundary
This calculator does not diagnose a condition, choose treatment, change medication, or determine that an urgent symptom is safe to monitor at home. Contact an appropriate health professional or local emergency service when the situation may be urgent.
Privacy
Entered health values and results stay in this browser tab. They are not placed in URLs, analytics, logs, local storage, session replay, or a cloud record by this calculator.
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