Ejection Fraction Calculator
Calculate cardiac ejection fraction from end-diastolic and end-systolic volumes.
Ejection Fraction (EF)
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Stroke Volume (SV)
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Formula
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Interpretation
What Ejection Fraction Measures
Ejection fraction (EF) is a measurement of how efficiently the heart pumps blood with each beat. Specifically, it describes the percentage of blood that the left ventricle pumps out of its filled volume during a single contraction. It is one of the most important indicators of overall heart pumping function.
When the heart relaxes and fills with blood, it holds its largest volume — the end-diastolic volume (EDV). When it contracts and ejects blood, the remaining amount is the end-systolic volume (ESV). The difference between these two volumes is the stroke volume, and ejection fraction expresses that stroke volume as a percentage of the filled volume.
Normal Ranges and Classification
Ejection fraction is generally grouped into the following ranges, which help describe heart pumping efficiency:
Normal (50% or higher)
A healthy left ventricle typically ejects 50% or more of its blood with each beat.
Mildly reduced (41–49%)
Pumping efficiency is slightly below the normal range.
Moderately reduced (30–40%)
The heart pumps a noticeably smaller fraction of blood with each beat.
Severely reduced (below 30%)
Pumping efficiency is well below normal.
The Ejection Fraction Formula
Ejection fraction is calculated from the stroke volume and the end-diastolic volume:
Stroke Volume (SV) = EDV − ESV
Ejection Fraction (EF) = (SV / EDV) × 100
For example, with an EDV of 120 mL and an ESV of 50 mL, the stroke volume is 70 mL and the ejection fraction is (70 / 120) × 100 ≈ 58.3%, which falls in the normal range.
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Medical Disclaimer: This ejection fraction calculator is provided for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Ejection fraction values depend on accurate volume measurements obtained through clinical imaging, and interpretation requires the full clinical context. This tool is not a diagnosis and must not be used to make health decisions. Always consult a qualified healthcare professional or cardiologist regarding heart function and any medical concerns.