Calculates cardiac index from cardiac output and body surface area.
Overview
Calculates cardiac index from cardiac output and body surface area.
Clinical Significance
Normalises cardiac output to body size. Clinical meaning depends on measurement method, loading conditions and metabolic state.
When to Use
- Use when the required measurements are available, reliable and clinically relevant.
How It Is Calculated
- CI = cardiac output / body surface area.
Interpretation
- Normalises cardiac output to body size. Clinical meaning depends on measurement method, loading conditions and metabolic state.
Worked Example
Enter valid values in the displayed units. MedicalC then applies: CI = cardiac output / body surface area.
Limitations
- The result does not establish a diagnosis or mandate treatment.
- Measurement error may be more important than arithmetic precision.
- Published thresholds may differ between populations and settings.
Clinical Pearls
- Document the source values and units with the final result.
- Review trends rather than isolated values where appropriate.
Common Mistakes
- Using the wrong unit.
- Combining values from different time points.
- Applying the result outside the intended measurement or clinical context.
Frequently Asked Questions
What does this calculator provide?
Calculates cardiac index from cardiac output and body surface area.
What formula is used?
CI = cardiac output / body surface area.
Can the result be used alone?
No. It must be interpreted with the full clinical assessment and appropriate investigations.
What is the main limitation?
The result depends on accurate source measurements, correct units and appropriate clinical applicability.
References
- Standard haemodynamic relationship. — Primary, supporting or authoritative reference for the implemented relationship.
Reviewed by: MedicalC Clinical Editorial Team
Last reviewed: July 2026