All calculations must be re-checked by hand and should not be used alone to guide patient care. See disclaimer for more. Light green = required. Once required data is entered, click anywhere for results.

Equations

Scores

Corrected QT for HR (QTC)

Heart Rate BPM
QT Interval msec
Corrected QT msec

Corrected QT (QTC) = Bazett's Formula = QT Interval / √ (RR interval)
RR Interval = 60/HR

Normal QTc ≤ 440 msec. A longer QTc puts the patient at increased risk for torsade de pointes.

Some causes of prolonged QT: