Hemodynamics

Cardiac Index (CI) Calculator

Cardiac output scaled to body size, so flow can be compared between a small and a large patient.

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Turn on JavaScript to use this calculator, or open it in the web app.

Formula

CO / BSA

Reference: Normal 2.5–4.0

How it is used

• Normal Cardiac Index is 2.5–4.0 L/min/m².

Decreased CI (< 2.2 L/min/m²)

• Indicates hypoperfusion (cardiogenic shock, hypovolemic shock, or late distributive shock). Consider inotropes (dobutamine, milrinone) or mechanical circulatory support if filling pressures are adequate.

Elevated CI (> 4.0 L/min/m²)

• Indicates a hyperdynamic state (sepsis, liver failure, severe anemia, thyrotoxicosis).

Same formula as the app. Open it in the web app.

Related one-pagers

• Hemodynamic NormalsCI · 2.5–4.0 · L/min/m²
• Shock Types at a GlanceC: Classic · Hypoperfused; needs a drug or device · Lactate ≥2, cold, urine <30 mL/h; CI <2.2, PCWP >15
• ECMO EssentialsCircuit vs heart · In series; native heart must pump · In parallel; bypasses heart and lungs
• Pediatric Assessment and EmergenciesCirculation to skin · Pallor, mottling, cyanosis

Related calculators

• Cardiac Output (Fick Principle)
• Cerebral Perfusion Pressure (CPP)
• Mean Arterial Pressure (MAP)
• Oxygen Delivery (DO₂)
• Pulmonary Vascular Resistance (PVR)
• QTc (Bazett)
• Shock Index
• Stroke Volume (SV)

For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Verify results independently and follow your local protocols and medical direction. Not a substitute for clinical judgment.