Enter your Heart Rate (in bpm or Hz) and Stroke Volume (in mL or L) to calculate your Cardiac Output — how much blood your heart pumps per minute — alongside an estimated Cardiac Index and Ejection Fraction estimate based on a normal stroke volume baseline.
Cardiac Output
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Cardiac Index (estimated)
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EF Estimate (normal SV)
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Cardiac output is the volume of blood pumped by the heart per minute. It's calculated by multiplying heart rate by stroke volume and is crucial for assessing cardiovascular function and the heart's ability to meet the body's metabolic demands.
Normal cardiac output at rest is typically 4-8 L/min (4000-8000 mL/min) for adults. This can vary based on body size, fitness level, age, and other factors. Athletes may have higher values due to increased stroke volume.
Stroke volume is the amount of blood pumped per heartbeat, typically 60-80 mL in healthy adults. Since cardiac output = heart rate × stroke volume, increasing stroke volume directly increases cardiac output even if heart rate remains constant.
Cardiac output is influenced by heart rate, stroke volume, blood volume, venous return, contractility of the heart muscle, and afterload (resistance against which the heart pumps). Exercise, medications, and disease states can all affect these parameters.
Cardiac output is measured to assess heart function in conditions like heart failure, shock, during surgery, or in critical care settings. It helps guide treatment decisions and monitor patient response to interventions.
Cardiac output is the absolute volume pumped per minute, while cardiac index is cardiac output normalized to body surface area (usually 2.5-4.0 L/min/m²). Cardiac index allows better comparison between individuals of different sizes.
This calculator provides theoretical values based on the basic formula CO = HR × SV. For clinical decision-making, direct measurement using thermodilution, echocardiography, or other advanced methods is recommended for accuracy.