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Corrected QT Interval (QTc) Using Bazett's Formula Calculator

QTc = QT / √RR — heart-rate corrected QT interval.

Calculates the corrected QT interval QTc = QT / √(RR), where RR = 60/HR (seconds). Normal QTc: <440 ms (male), <460 ms (female). Prolonged QTc >500 ms → high risk.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

Inputs

ms
bpm

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

QTc = QT / √RR (Bazett)

In depth

Calculates the corrected QT interval QTc = QT / √(RR), where RR = 60/HR (seconds). Normal QTc: <440 ms (male), <460 ms (female). Prolonged QTc >500 ms → high risk.