Cardiac Index Calculator
Calculate Cardiac Index — cardiac output normalised to body surface area (CO/BSA) for fair comparison across body sizes.
What is Cardiac Index?
Cardiac Index is the more useful clinical metric than raw cardiac output because it controls for body size. A fit, large athlete and a small frail patient can both have CO 6 L/min, but very different cardiac performance per square metre of body. Normal CI is 2.5–4.0 L/min/m²; values below 2.0 indicate cardiogenic shock.
How is it calculated?
CI = CO / BSA. Compute BSA with the Mosteller formula or any reference table. Healthy adults: 2.5–4.0 L/min/m².
Frequently Asked Questions
- How is BSA calculated?
- Mosteller: √(height × weight / 3600).
- Does CI vary with exercise?
- Yes — it can triple.
- Why prefer CI over CO?
- CI is body-size-neutral.