Hemodynamics

Stroke Volume Index (SVI) Calculator

Stroke volume scaled to body size, so pump performance can be compared between patients of different sizes.

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

SV / BSA

Reference: Normal 33–47

How it is used

• Normal SVI is 33–47 mL/m²/beat.
• A low SVI points to poor filling, weak contraction or high afterload; look at the filling pressures and the SVR to tell which.
• Fluid responsiveness: stroke volume or output rising more than 10% after a fluid challenge or passive leg raise marks a responder.

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

Related one-pagers

• Hemodynamic NormalsSVI · 33–47 · mL/m²/beat
• Shock Types at a GlanceLost volume lowers venous return and stroke volume; baroreceptors raise heart rate and SVR. Vasoconstriction holds diastolic pressure while systolic falls, so pulse pressure narrows before SBP drops, and young adults can lose 30% of blood volume first. Tachycardia, cool skin and a shock index (HR ÷ SBP) above 0.9–1.0 are the early signs. Non-hemorrhagic losses (GI, burns, DKA, diuresis) get balanced crystalloid (SMART 2018) and treatment of the cause.

Related calculators

• Cardiac Index (CI)
• Cardiac Output (Fick Principle)
• Cardiac Output (HR × SV)
• Cerebral Perfusion Pressure (CPP)
• Coronary Perfusion Pressure
• Ejection Fraction (EF)
• Mean Arterial Pressure (MAP)
• Oxygen Delivery (DO₂)

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