Back to calculator
Clinical & CardioGenerated accuracy model review: 2026-05-06
QTc Calculator accuracy and testing
This page documents how Calwarden builds trust for this calculator: source notes, regression-style default tests, limitations, assumptions, unit handling, rounding, and visible change history.
Formula source
- Bazett: QT / √RR. Fridericia: QT / ∛RR. (RR = 60/HR)
Test cases
Default input regression check
Generated from the checked-in default inputs and calculate function.
Inputs
- QT Interval: 350 msec
- Heart Rate: 60 bpm
Expected outputs
- QTc (Bazett): 350 msec
- QTc (Fridericia): 350 msec
- QTc (Framingham): 350 msec
Known limitations
- Not for diagnostic use. Automated calculations should always be verified by a qualified professional. T-wave morphology can affect manual measurement accuracy.
Assumptions
- The calculation assumes the QT interval was measured accurately from a readable ECG.
- Each correction formula has known strengths and weaknesses at very fast or very slow heart rates.
- QTc is a screening aid and should be interpreted with symptoms, rhythm context, medications, and electrolytes.
Unit handling
- QT Interval accepts values in msec.
- Heart Rate accepts values in bpm.
- QTc (Bazett) is displayed in msec.
- QTc (Fridericia) is displayed in msec.
- QTc (Framingham) is displayed in msec.
Rounding rules
- Number displays use up to 2 decimal places in the calculator UI.
Version history
1.0.0 - 2026-05-06
Generated accuracy and testing page from the current qtc-calculator calculator definition.
Change log
2026-05-06
Published default regression test documentation and metadata fallbacks for QTc Calculator.
Calculator transparency
Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.