By Zencalcy Editorial TeamLast reviewed About us
Stroke volume is the amount of blood the left ventricle ejects with each beat. It is calculated by subtracting the volume left at the end of contraction from the volume present at the end of filling. This calculator returns stroke volume in millilitres and shows the subtraction.
Blood ejected per beat from EDV and ESV.
SV = EDV − ESV
End-diastolic volume is the blood in the ventricle before contraction, and end-systolic volume is what remains after it. The difference is the ejected volume. A normal resting stroke volume is often around 60–100 mL, but it depends on body size, filling and contractility, so indexed values are more comparable between people.
| Symbol | Meaning |
|---|---|
| EDV | End-diastolic volume in millilitres. |
| ESV | End-systolic volume in millilitres. |
| SV | Stroke volume in millilitres per beat. |
Stroke volume = 120 − 50 = 70 mL per beat. With EDV 100 mL and ESV 40 mL, stroke volume is 60 mL. The first ventricle ejects a larger volume per beat, but the comparison only becomes meaningful when indexed to body size and read alongside heart rate.
Stroke volume is a difference, which means it can stay the same while its components change in opposite directions. A dilated ventricle may hold more blood at the end of diastole and retain more at the end of systole, producing a normal difference despite poor contraction. A small, stiff ventricle may have low volumes but a preserved difference. Looking at EDV and ESV separately therefore adds information that the subtraction alone hides. In practice, stroke volume is usually indexed to body surface area and interpreted with ejection fraction and chamber dimensions. It also depends on loading conditions: a fluid bolus can raise it, while a high afterload can lower it. That is why serial measurements under similar conditions are more informative than a single value, and why the number should not be read as a stand-alone verdict on cardiac health.
Continue with the Mean Arterial Pressure Calculator, Pulse Pressure Calculator, or the QTc Calculator — or browse more cardiology tools and all health calculators.
A resting value of roughly 60–100 mL is often quoted for adults, but the range varies widely with body size, fitness, filling and contractility. An indexed stroke volume is more useful when comparing people of different sizes.
Blood pressure, ECG and risk scores are screening aids, not diagnoses. A single reading can be misleading; trends and proper technique matter. Scores estimate population risk and do not replace clinical assessment, anticoagulation decisions or emergency care.
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Last reviewed: September 2026. See how we build and check every tool on the about page.
Content updated: September 2026