Ejection Fraction Calculator

Ejection fraction (EF) is the percentage of blood pumped out of the left ventricle with each heartbeat. A normal heart does not eject all the blood it contains. It fills to an end-diastolic volume (EDV) and contracts down to an end-systolic volume (ESV), ejecting the difference.

EF = (EDV - ESV) / EDV × 100%

Stroke volume (SV) = EDV - ESV. This is the actual volume of blood ejected per beat.

Cardiac output (CO) = SV × heart rate. At rest with a heart rate of 70 bpm and stroke volume of 70 mL: CO = 4,900 mL/min ≈ 4.9 liters/minute, which is typical.

How the echo report grades it. The American Society of Echocardiography’s 2015 chamber guideline gives normal a different floor for men and women:

So a 53% is normal on a man’s report and mildly abnormal on a woman’s. Above the normal top, around 75% and up, the heart is called hyperdynamic, which can be fitness, anaemia, a fast heart or a thick-walled ventricle.

The heart failure labels are a separate scale, set by the 2021 Universal Definition of Heart Failure and the 2022 American Heart Association and American College of Cardiology guideline:

• HFrEF, heart failure with reduced ejection fraction: 40% or below. This used to be called systolic heart failure.
• HFmrEF, mildly reduced: 41 to 49%.
• HFpEF, preserved: 50% or above.
• HFimpEF, improved: someone who was at 40% or below and is now above it.

HFrEF is the one with four drug classes proven to lower the death rate: ACE inhibitors or ARNIs (angiotensin receptor and neprilysin inhibitors), beta-blockers, mineralocorticoid receptor antagonists, and SGLT2 inhibitors.

HFpEF is a stiff ventricle that fills poorly rather than a weak one that empties poorly, and it is roughly half of all heart failure. For years no drug helped it. SGLT2 inhibitors were the first to cut hospital admissions, in the EMPEROR-Preserved and DELIVER trials.

EF is measured by echocardiography, cardiac MRI, or nuclear imaging. Echocardiography is most common given its availability and lack of radiation exposure.

This calculator is for educational purposes. Clinical decisions require physician evaluation and imaging confirmation.