Corrected QT Interval (QTc) Calculator
To calculate the corrected QT Interval (QTc) enter the duration of the QT Interval (milliseconds) and Heart Rate.
This formula is only valid for Electrocardiograms with Regular Rhythm.
Corrected QT Interval (QTc)
- Prolonged corrected QT: Greater than 460 ms in children under the age of 15, 450 ms in men, and 470 ms in women.
- Short QTc Interval: Less than 340ms is accepted as pathological.
How to use the corrected QT Calculator
Enter the measure of the QT Interval (from the beginning of the QRS complex to the end of the T wave) and the Heart Rate of the Electrocardiogram.

Example: Calculate QT Interval, from the beginning of the QRS to the end of the T wave