Enter Cardiac Output Values
Example Data Table
| Scenario | Heart Rate | Stroke Volume | Cardiac Output | Comment |
|---|---|---|---|---|
| Resting adult example | 70 bpm | 70 mL | 4.90 L/min | Common resting estimate |
| Higher exercise demand | 120 bpm | 100 mL | 12.00 L/min | May rise with activity |
| Lower flow example | 58 bpm | 55 mL | 3.19 L/min | Needs clinical context |
Formula Used
Stroke volume method: Cardiac Output = Heart Rate × Stroke Volume ÷ 1000
Fick method: Cardiac Output = VO₂ ÷ (CaO₂ − CvO₂) ÷ 10
Body surface area: BSA = √((Height in cm × Weight in kg) ÷ 3600)
Cardiac index: Cardiac Index = Cardiac Output ÷ BSA
Mean arterial pressure: MAP = (SBP + 2 × DBP) ÷ 3
Systemic vascular resistance: SVR = ((MAP − CVP) ÷ Cardiac Output) × 80
How to Use This Calculator
- Select the calculation method.
- Enter heart rate and stroke volume for the simple method.
- Enter VO₂, CaO₂, and CvO₂ for the Fick method.
- Add height and weight to calculate indexed results.
- Add blood pressure and CVP to estimate MAP and SVR.
- Press the calculate button.
- Review the result above the form.
- Use the CSV or PDF button to export your report.
Cardiac Output Guide
Understanding Cardiac Output
Cardiac output describes how much blood the heart pumps each minute. It connects heart rate, stroke volume, oxygen delivery, and circulation demand. A larger body often needs more flow. Exercise, fever, anxiety, pregnancy, fluid balance, and medicines can change the value. This calculator gives organized estimates for study, screening, and record keeping.
Why This Estimate Matters
Blood flow supports oxygen movement to the brain, muscles, kidneys, and other organs. A very low estimate may suggest weak pumping, low volume, or measurement error. A very high estimate may appear during exercise, stress, anemia, infection, or other high demand states. The result should always be reviewed with symptoms, blood pressure, oxygen status, and clinical context.
Calculation Choices
The stroke volume method is simple. It multiplies heart rate by the amount of blood ejected per beat. The Fick method uses oxygen consumption and the oxygen content difference between arterial and venous blood. Fick values can be more technical because they require reliable oxygen data. Both methods can be indexed to body surface area.
Using Results Safely
Cardiac index divides cardiac output by body surface area. This helps compare people of different sizes. Stroke volume index does the same for each beat. Systemic vascular resistance can be estimated when blood pressure and central venous pressure are supplied. These extra values add context, but they do not replace medical testing.
Best Practices
Enter values from trusted measurements. Avoid mixing resting and exercise numbers. Keep units consistent. Repeat calculations when a value seems unusual. Save the report when you need documentation. Use the example table to understand common ranges, but remember that ranges vary by source, condition, and patient needs.
Practical Interpretation
A single number rarely tells the whole story. Resting cardiac output can look different after exercise, dehydration, illness, or caffeine. Trends are usually more useful than one isolated entry. Compare results from the same method when possible. Note the date, posture, and measurement source. For patients with chest pain, fainting, severe breathlessness, blue lips, confusion, or very low blood pressure, seek urgent care instead of relying on a web calculator. This guidance is educational and supports safer discussions with clinicians only.
FAQs
What is cardiac output?
Cardiac output is the amount of blood pumped by the heart each minute. It is usually shown in liters per minute.
What is the common formula?
The common formula is cardiac output equals heart rate multiplied by stroke volume, then divided by 1000 for liters per minute.
What is stroke volume?
Stroke volume is the amount of blood pushed from the heart with each beat. It is usually measured in milliliters.
What is cardiac index?
Cardiac index adjusts cardiac output for body surface area. It helps compare blood flow between people of different sizes.
What is the Fick method?
The Fick method estimates blood flow using oxygen consumption and the difference between arterial and venous oxygen content.
Can this calculator diagnose heart disease?
No. It is only an educational tool. Medical decisions need professional review, symptoms, tests, history, and clinical judgment.
Why add height and weight?
Height and weight help estimate body surface area. That allows cardiac output to be converted into cardiac index.
When should urgent care be considered?
Seek urgent care for chest pain, fainting, severe breathlessness, confusion, blue lips, or very low blood pressure.