Ejection Fraction Calculator
From volume to percentage. See the fraction pumped out per beat.
Your Measurements
Illustrative equipment — enter your measured or estimated values.
What the Numbers Mean
EDV · After filling
Volume in the ventricle before contraction.
ESV · After contraction
Volume remaining after contraction.
Use the Right Inputs
- Use millilitres for both volumes.
- EDV must be greater than zero.
- ESV must be between zero and EDV.
Your Ejection Fraction
Calculated from the volumes entered · rounded to 2 decimals.
Ejected
Remaining
Shares of EDV, not clinical reference ranges.
Enter valid volumes to show the distribution.
The Two Measurements
—After filling
—After contraction
Illustrative images; volumes are supplied by the user.
How Is This Calculated?
EF = (EDV − ESV) / EDV × 100
Blood Ejected per Beat
Divide the ejected volume by the volume after filling.
A Closer Look at the Measurements
Obtain the volumes
Measure EDV and ESV using an appropriate method.
Match the assessment
Use volumes from the same ventricle and assessment.
Review the result
Consider the result and review it with a healthcare professional.
Calculation & Assumptions
Formula: EF = (EDV − ESV) / EDV × 100
Units: Percentage (%).
This method uses EDV and ESV in mL.
Input limits & precision
EDV must be greater than 0 and at most 10,000 mL. ESV must be between 0 and EDV. Both inputs support up to six decimal places. These are software limits, not clinical reference ranges. The calculation retains an exact reduced fraction for the percentage. The main result is rounded to two decimals; tiny positive results display as < 0.005% instead of zero. The volume distribution uses the unrounded proportions. Equal input volumes give a mathematical EF of 0%; ESV of 0 gives 100%. These are arithmetic outcomes, not clinical interpretations.
Frequently asked questions
What is ejection fraction?
Ejection fraction is the proportion of the end-diastolic volume ejected during one contraction, expressed as a percentage. This page calculates EF = (EDV − ESV) / EDV × 100.
Is EF the same as stroke volume?
No. Stroke volume is EDV minus ESV, expressed as a volume per beat. Ejection fraction divides that volume by EDV and expresses the ratio as a percentage.
Where do EDV and ESV come from?
Use clinically measured or estimated volumes from the same ventricle, assessment and compatible measurement method. Imaging methods and measurement assumptions can affect the reported result. The photographs here are illustrative.
More questions (5)
What does the Ejection Fraction calculate?
Ejection Fraction Calculator — free online calculator.
Which values should I enter?
Enter End-diastolic volume, End-systolic volume using the units and format shown beside each field.
What formula does this calculator use?
The calculator uses the following relationship: EF = (EDV − ESV) ÷ EDV × 100.
Why might my result differ from another source?
Results can differ because measurement methods, rounding and assumptions vary. This calculator is an estimate and is not a medical diagnosis.
Does the result update automatically?
Yes. Changing an input updates the result using the same calculation engine shown on this page.
Sources & References
BookshelfLeft Ventricular Ejection FractionStatPearls · Clinical backgroundCleveland
ClinicEjection fraction and stroke volumeHealth Library · Measurement context
References provide context, not endorsement.