QTc Calculator
Bazett QTc calculation for ECG education — not for self-diagnosis.
Use the calculator below, then review the formula, a numeric example, and the reference table to understand how the corrected qt (qtc) result is produced.
Educational tool only. It does not replace advice from a licensed clinician, dietitian, or exercise physiologist.
Calculator inputs
Result
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What is this calculator?
Bazett QTc calculation for ECG education — not for self-diagnosis. The formula, a worked example, and a reference table are below. Results are for education only, not medical advice.
How it works
Bazett: QTc(ms) = QT(ms) ÷ √(RR(s)) where RR(s) = RR interval in seconds (RR_ms ÷ 1000).
Example
QT 400 ms, RR 800 ms QTc ≈ 400 / 0.8 ≈ 447 ms (educational arithmetic).
Reference Table
| Value | Meaning |
|---|---|
| QT interval | Heart repolarization phase |
| Bazett limits | Less accurate at extreme HR |
| Machine QTc | May differ from manual calipers |
FAQ
Is my ECG normal?
Only a qualified professional should interpret ECGs.
Drugs prolong QT?
Many medications and electrolytes interact—ask your clinician.
Other QTc formulas?
Fridericia and others exist; institutions standardize choice.
Symptoms?
Syncope or palpitations need urgent evaluation, not online tools.