ECG QTc Calculator (Bazett, Fridericia, Framingham, Hodges)

The QT interval on an electrocardiogram (ECG) represents the time it takes for the heart ventricles to depolarize and repolarize. However, this interval naturally shortens as the heart rate increases and lengthens as it slows down. To clinically assess the risk of dangerous arrhythmias like Torsades de Pointes, cardiologists must calculate the "Corrected" QT interval (QTc), which normalizes the measurement to a standard heart rate of 60 beats per minute.

This tool is a powerful utility for clinicians, providing results from the four most respected formulas simultaneously. While Bazett's formula is the most common, it tends to overcorrect at high heart rates. Fridericia and Framingham are often preferred for tachycardia. By seeing all values side-by-side, medical professionals can make a more informed decision regarding drug toxicity (e.g., from certain antibiotics or antipsychotics) or congenital Long QT Syndrome.

Where QT is in seconds and RR is the interval between beats in seconds (60/HR).