ECG Corrected QT Interval (QTc: Bazett, Fridericia, Framingham & Hodges) Calculator

Compare Bazett and Fridericia QTc intervals across tachycardia and bradycardia.

Bazett Corrected QT Interval (QTcB)
444.67 ms
Fridericia QTc (QT / ∛RR) 425.64 ms
Framingham Linear QTc 425.54 ms
R-R Cycle Length 769.23 ms
Inputs
ms
Uncorrected QT interval measured on 12-lead ECG in milliseconds.
bpm
Ventricular heart rate in beats per minute (bpm).
Results & Graph
Bazett Corrected QT Interval (QTcB)
444.67 ms
Fridericia QTc (QT / ∛RR)
425.64 ms
Framingham Linear QTc
425.54 ms
R-R Cycle Length
769.23 ms

Bazett Corrected QT Interval (QTcB)

Graph 1 • Measured Qt Ms Sensitivity Recalculates the domain equation across 50% to 150% of the primary input while holding other parameters constant.
0 ms 360.2 ms 720.4 ms 50%: 222.33 ms 222.3 50% 75%: 333.5 ms 333.5 75% 100%: 444.67 ms 444.7 100% 125%: 555.84 ms 555.8 125% 150%: 667 ms 667 150%
Graph 2 • Primary & Supporting Metric Comparison Compares the primary output alongside supporting domain benchmarks.
Bazett Corrected QT Interval (QTcB) 444.67 ms Fridericia QTc (QT / ∛RR) 425.64 ms Framingham Linear QTc 425.54 ms R-R Cycle Length 769.23 ms
Graph 3 • Exact Output Table & Units Displays each calculated output in its exact domain unit.
Bazett Corrected QT Interval (QTcB)444.67 msFridericia QTc (QT / ∛RR)425.64 msFramingham Linear QTc425.54 msR-R Cycle Length769.23 ms
Summary: At 78 bpm (RR = 0.769 s) and QT = 390 ms, Bazett QTc is 444.7 ms, Fridericia QTc is 425.6 ms, and Framingham QTc is 425.5 ms.
Summary: At 78 bpm (RR = 0.769 s) and QT = 390 ms, Bazett QTc is 444.7 ms, Fridericia QTc is 425.6 ms, and Framingham QTc is 425.5 ms.
⚡ Send result to: Molarity, HP & Dew Point →Sleep & eGFR Reference →Scientific →
Interactive chart & math engine powered by CalculatorGraph

Formula & Mathematical Methodology: ECG QTc Interval Reference Equation

RRsec = 60 / HR
QTcBazett = QT / √RR
QTcFridericia = QT / RR1/3
RR_sec = 60 / HR; QTc_Bazett = QT / √RR; QTc_Fridericia = QT / RR^(1/3)
  • measuredQtMs: Measured Qt Ms (ms)
  • heartRateBpm: Heart Rate Bpm (bpm)

Rounding: Laboratory and clinical equations retain full floating-point precision and round displayed results to 2 decimal places.

Worked Example: Reference Calculation: ECG QTc Interval

Compare Bazett and Fridericia QTc intervals across tachycardia and bradycardia.

  1. Enter the reagent concentrations, assay readings, or clinical laboratory parameters.
  2. Compute the standard formula: RR_sec = 60 / HR; QTc_Bazett = QT / √RR; QTc_Fridericia = QT / RR^(1/3).
  3. Review the primary result, supporting reference intervals, and 3 SVG visualizations.
Result: Evaluates ECG QTc Interval via RR_sec = 60 / HR; QTc_Bazett = QT / √RR; QTc_Fridericia = QT / RR^(1/3).

Frequently Asked Questions

What formula is used by the ECG Corrected QT Interval (QTc: Bazett, Fridericia, Framingham & Hodges) Calculator?

It computes RR_sec = 60 / HR; QTc_Bazett = QT / √RR; QTc_Fridericia = QT / RR^(1/3) and plots three custom SVG graphs showing parameter sensitivity and component breakdowns.

Can I compare different reagent dilutions or lab scenarios side by side?

Yes. Use the "Compare (0/3)" button to pin up to 3 scenarios side by side.

Are entered values stored on any server?

No. Every calculation runs 100% locally in your browser.

Health & Fitness · Clinical Diagnostics & Scoring

ECG Corrected QT Interval (QTc: Bazett, Fridericia, Framingham & Hodges) Calculator: inputs, method, and how to read the result

Compare Bazett and Fridericia QTc intervals across tachycardia and bradycardia.

Choose inputs for the case you are checking

The defaults are illustrative. Replace them with values for your case and keep the units shown beside each field.

  • Measured Qt Ms: Uncorrected QT interval measured on 12-lead ECG in milliseconds.
  • Heart Rate Bpm: Ventricular heart rate in beats per minute (bpm).

What the calculation includes

With the default values shown, Bazett Corrected QT Interval (QTcB) is 444.67 ms. The calculation follows ECG QTc Interval Reference Equation; the formula and variable definitions above show how the inputs combine.

One-input check: With the other defaults held constant, changing Measured Qt Ms from 390 ms to 429 ms changes Bazett Corrected QT Interval (QTcB) from 444.67 ms to 489.14 ms. This is a comparison inside the calculator's stated model, not a prediction.

Where to use caution

  • Uses standard IUPAC atomic weights, 25°C (298.15 K) reference thermodynamics, and published clinical literature equations.
  • Educational and laboratory reference tool only; clinical scoring calculators do not replace professional medical judgment or institutional protocols.

Scope: IUPAC / NIH Laboratory & Clinical Reference Standard Check the assumptions and limitations against your situation before relying on the estimate.

More in Health & Fitness: Molarity, Density, Engine Horsepower & Dew Point / Weather Calculator, Sleep Cycle Planner & Clinical eGFR (2021 CKD-EPI) Reference Calculator, Scientific Calculator.