Stroke Volume Calculator (EDV − ESV, or cardiac output ÷ heart rate)

Understanding the stroke volume calculator — concept and principle

Stroke volume (SV) is the amount of blood the left ventricle pumps out with each beat. This calculator works it out either from end-diastolic and end-systolic volumes (as measured by echocardiography or MRI) or from cardiac output and heart rate, and adds the stroke volume index, ejection fraction and cardiac output.

Filled minus left over: with the default inputs the result is 70 mL (EF 58.3% · CO 4.9 L/min).

How it is calculated

From volumes: SV (mL) = end-diastolic volume (EDV) − end-systolic volume (ESV); ejection fraction = SV ÷ EDV

From cardiac output: SV (mL) = cardiac output (L/min) × 1,000 ÷ heart rate

Stroke volume index = SV ÷ body surface area

Cardiac output (volume method) = SV × heart rate ÷ 1,000

The principle

The ventricle fills to its end-diastolic volume, then contracts and leaves the end-systolic volume behind; the difference is what left with the beat. Cardiac output is the volume pumped per minute, so dividing it by beats per minute gives volume per beat. Stroke volume rises with filling (preload) and the strength of contraction, and falls when the arteries resist more (afterload) or the heart beats very fast and has less time to fill.

Worked example

Default inputs: volume method, EDV 120 mL, ESV 50 mL, heart rate 70, BSA 1.9 m².

SV = 120 − 50 = 70 mL → Within the usual range (60–100 mL).
Ejection fraction = 70 ÷ 120 = 58.3%.
Stroke volume index = 70 ÷ 1.9 = 36.8 → 37 mL/m².
Cardiac output = 70 × 70 ÷ 1,000 = 4.9 L/min.

Each point is the calculator re-run with only “End-systolic volume, ESV (mL)” changed; the gold point is the default example. Change the inputs above and this chart follows your numbers.

End-systolic volume, ESV (mL)	Stroke volume (mL/beat)
12.5	108
25	95
37.5	83
50	70
62.5	58
75	45
100	20

How to read the result

Where does your result fall?

A typical resting adult stroke volume is 60–100 mL per beat, and the index is usually 33–47 mL/m². Athletes often have larger stroke volumes and slower heart rates. A low stroke volume can come from a weak heart, low filling or a valve problem, so it is interpreted with the rest of the assessment.

Common mistakes

Mixing the two methods' inputs.
Entering cardiac output in mL/min instead of L/min.
Comparing stroke volumes of people of very different sizes without indexing.

Keep in mind: This is a calculation aid, not a diagnosis. Heart measurements are interpreted by a cardiologist.

Frequently asked questions

What is a normal stroke volume?

About 60–100 mL per beat in adults at rest.

Why do athletes have a slow pulse?

Their larger stroke volume lets the heart pump the same output with fewer beats.

How is stroke volume measured?

By echocardiography, MRI, or derived from cardiac output measurements.

Sources: Klabunde RE, Cardiovascular Physiology Concepts, 3rd ed., Wolters Kluwer, 2021 (stroke volume and cardiac output) · Edwards Lifesciences, "Normal Hemodynamic Parameters and Laboratory Values"

Checked 9 Nov 2026. Edwards Lifesciences Clinical Education, “Normal Haemodynamic Parameters and Laboratory Values” (2022, PP--EU-4269 v1.0): SV = CO/HR × 1000, 60–100 mL/beat; SVI 33–47 mL/m²/beat; EF = SV/EDV.

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