Cardiology Calculators
Cardiology calculators for ECG intervals, haemodynamic estimates, and common cardiovascular measures — with formulas, worked examples, and FAQs.
QTc Calculator
Calculate corrected QT interval using Bazett, Fridericia, or Framingham formulas
Mean Arterial Pressure (MAP)
Calculate MAP from systolic and diastolic blood pressure for hemodynamic assessment
CHA₂DS₂-VASc Score
Stroke risk stratification in atrial fibrillation to guide anticoagulation therapy
Cardiac Output
Calculate cardiac output from stroke volume and heart rate
How Cardiology Calculations Work
These cardiology calculators help standardise common cardiovascular measurements used in assessment and documentation. They provide quick, accurate estimates for ECG interval corrections and hemodynamic parameters.
Typical inputs include heart rate, blood pressure, ECG intervals (QT/RR), and standard units. These calculators support calculation checking and documentation, but do not replace clinical assessment or clinical decisions by themselves.
QTc (Bazett)
QTc corrects the QT interval for heart rate using the RR interval. It helps compare QT at different heart rates.
Example question: QT is 420 ms and RR is 0.80 seconds. What is QTc using Bazett's formula?
(Use consistent units; QT often in seconds for calculation)
Worked example:
Result: Answer: QTc ≈ 469 ms
💡 Tip: Convert units first—then apply the formula.
Mean arterial pressure (MAP)
MAP estimates average arterial pressure using systolic and diastolic readings.
Example question: BP is 120/80 mmHg. What is the MAP?
Worked example:
Result: Answer: MAP ≈ 93 mmHg
💡 Tip: Diastolic counts twice in this estimate.
Shock index
Shock index is heart rate divided by systolic blood pressure. It's a quick relationship check used in assessment.
Example question: Heart rate is 110 bpm and systolic BP is 100 mmHg. What is the shock index?
Worked example:
Result: Answer: Shock index = 1.10
💡 Tip: HR ÷ systolic BP.
When These Calculators Are Used
- •Checking ECG interval corrections (QTc) using common formulas
- •Converting BP readings into MAP for documentation
- •Quick ratio checks such as shock index during assessment
- •Teaching/study of core cardiology metrics and formulas
- •Double-checking arithmetic and unit conversions during busy shifts
Clinical safety note
These calculators support calculation checking and documentation but do not replace clinical assessment or local protocols. Confirm units and source measurements before calculating. Examples on this page are for calculation practice only.
Related Calculator Categories
Frequently Asked Questions
Clinical reminder: Always follow local protocols and consult medication information sheets. These examples are for calculation practice only.