Stroke Volume Calculator — SV, Ejection Fraction & Cardiac Output
Stroke volume (SV) is the volume of blood the left ventricle ejects in one heartbeat. Calculate it from echocardiogram volumes (EDV − ESV) or from cardiac output and heart rate (CO ÷ HR), and see the ejection fraction.
Calculation method
mL
mL
Blood ejected per heartbeat — normal range 60–100 mL at rest
- 1
Stroke volume (EDV − ESV)
120 mL − 50 mL = 70 - 2
Ejection fraction
70 ÷ 120 × 100 = 58.3Fraction of end-diastolic volume ejected each beat; normal 55–70%.
How does this calculator work?
Stroke volume = EDV − ESV (from echo volumes) or CO × 1000 / HR (from output data), in mL. Normal adult resting SV is 60–100 mL. Ejection fraction (SV / EDV × 100%) should be 55–70% for healthy systolic function. Values below 40% suggest reduced ventricular function requiring clinical evaluation.
Formula
How this is calculated
Stroke volume is the difference between end-diastolic volume (EDV — how full the ventricle is at the end of passive filling) and end-systolic volume (ESV — the blood remaining after ejection): SV = EDV − ESV. Normal adult resting values are approximately EDV 120–130 mL and ESV 50–60 mL, giving SV around 60–70 mL per beat.
Alternatively, if cardiac output (CO, in litres per minute) and heart rate (HR, in bpm) are known, stroke volume is derived algebraically: SV (mL) = CO × 1000 / HR. A resting adult with CO = 5 L/min and HR = 70 bpm gives SV ≈ 71 mL — both methods should agree when values are from the same measurement.
Ejection fraction (EF = SV / EDV × 100%) is a key clinical index of systolic function. Normal EF is 55–70%. Values below 40% indicate heart failure with reduced ejection fraction (HFrEF). This calculator uses standard textbook formulas and does not account for valve regurgitation, bi-ventricular differences, or the specific imaging method used (Simpson’s biplane rule, Teicholz, etc.) — clinical interpretation should always be done by a qualified clinician.
Frequently asked questions
A healthy adult at rest has a stroke volume of roughly 60–100 mL per beat. During vigorous exercise it can rise to 150–200 mL in trained athletes, driven by increased venous return (Frank-Starling mechanism), greater sympathetic contractility, and reduced afterload from vasodilation in working muscles.
Ejection fraction (EF) is the percentage of end-diastolic volume pumped out per beat. Normal EF is 55–70%. An EF below 40% is classified as heart failure with reduced ejection fraction (HFrEF) and guides treatment such as ACE inhibitors, beta-blockers, and SGLT2 inhibitors. Heart failure with preserved EF (HFpEF, EF ≥50%) is a separate syndrome driven by diastolic dysfunction.
Preload (end-diastolic stretch, governed by venous return — more filling generally means stronger contraction per the Frank-Starling law), afterload (systemic vascular resistance opposing ejection — higher afterload reduces SV), and contractility (intrinsic myocardial strength, influenced by sympathetic activity and inotropic drugs such as dobutamine or digoxin).
TG we-Calculate Editorial Team. (2026). Stroke Volume Calculator — SV, Ejection Fraction & Cardiac Output [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/stroke-volume-calculator
TG we-Calculate Editorial Team. "Stroke Volume Calculator — SV, Ejection Fraction & Cardiac Output." TG we-Calculate. 2026. https://we-calculate.com/calculator/stroke-volume-calculator.
TG we-Calculate Editorial Team, "Stroke Volume Calculator — SV, Ejection Fraction & Cardiac Output," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/stroke-volume-calculator
@misc{wecalculate_stroke_volume_calculator, title = {Stroke Volume Calculator — SV, Ejection Fraction & Cardiac Output}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/stroke-volume-calculator}}, year = {2026}, note = {TG we-Calculate} }
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