About this Cardiac Index (CI)
Cardiac Output (L/min) measures how much blood the heart pumps, but it doesn't account for patient size. A 5L/min output is normal for a small person but low for a giant. Cardiac Index normalizes this by dividing by Body Surface Area (BSA).
Who this calculator is for
- Clinicians, students, and trainees reviewing hemodynamic measurements.
- People who already have a measured cardiac output and want the indexed value.
- Anyone learning why BSA matters when comparing cardiac performance between patients.
When to use it
- Use this calculator after obtaining cardiac output from echo, thermodilution, or another documented method.
- Use it when rounding or chart review calls for an indexed rather than absolute cardiac output.
- Use it to understand how changes in body size alter the interpretation of the same cardiac output.
How to use this calculator
- Enter the Cardiac Output (measured via echo or catheter).
- Enter the patient's Height and Weight to calculate BSA automatically.
- The result is the Cardiac Index in L/min/m².
Key assumptions
- This tool assumes the cardiac output value you enter was measured correctly before indexing.
- BSA is estimated with the Du Bois formula rather than measured directly.
- Cardiac index supports hemodynamic assessment, but it should be interpreted alongside the full clinical picture.
Accuracy and testing
Review formula sources, default test cases, assumptions, unit handling, rounding rules, and changelog for this calculator.
Key Features
- Instant Calculation
- Private & Secure
- Mobile Optimized
Things to Keep in Mind
For educational use only. Uses DuBois formula for BSA estimation.