Cardiac Output (Fick’s Formula) Calculator

What Is a Cardiac Output Calculator (Fick’s Formula)?

The Cardiac Output Calculator based on Fick's Formula estimates the amount of blood the heart pumps per minute (L/min), using measurable physiological variables. This includes arterial oxygen saturation (SaO₂), venous oxygen saturation (SvO₂), hemoglobin concentration, and heart rate. This method is widely used in clinical practice, particularly in critical care, cardiology, and anesthesiology.

How to Use the Cardiac Output Calculator

This calculator supports both metric and imperial units for height, weight, and hemoglobin. Select the units that apply to your data, input the relevant values, and click Calculate to compute the cardiac output in liters per minute (L/min).

Required Inputs

• Height – Measured in cm or inches
• Weight – Entered in kg or lbs
• Hemoglobin (Hb) – Select g/L or g/dL
• SaO₂ (%) – Arterial oxygen saturation, from ABG
• SvO₂ (%) – Mixed venous oxygen saturation, from PA catheter
• Heart Rate – Beats per minute (bpm)
• Age – Choose under or over 70 years

Cardiac Output Formula Used

The formula used is a clinical version of Fick’s Principle:

CO = [1.34 × Hb × (SaO₂ − SvO₂) × 10 × HR] / 100

This method assumes oxygen consumption (VO₂) is derived indirectly, based on the difference in oxygen content between arterial and venous blood and the hemoglobin level. The calculator gives output in L/min, which is the standard unit for cardiac output in physiology.

Features of This Tool

• Auto unit conversion for height, weight, and Hb
• Interactive buttons for age classification
• Real-time calculation with validation
• Result shown with appropriate unit (L/min)
• Displays full calculation formula for reference

This cardiac output calculator is designed for clinicians, researchers, and medical students needing a quick, reliable assessment of heart pumping efficiency using standard Fick-based methodology.