Cardiology tool

QTc Correction Calculator

Compare common QT correction formulas and frame prolonged-QTc risk more clearly.

Measured QT (ms)Heart rate (bpm)Sex-specific threshold

Bazett

470 ms

Commonly used, but tends to overcorrect at high heart rates.

Fridericia

452 ms

Often preferred when the heart rate is fast or irregular.

Framingham

451 ms

Linear correction often used for comparison in research and cardiology review.

Interpretation

Prolonged

Common adult thresholds: prolonged QTc is often considered >450 ms in men or >470 ms in women; QTc >500 ms is markedly prolonged and associated with higher torsades risk.