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Stroke Volume (SV) is a core measure of cardiac function: the amount of blood the left ventricle actually ejects with each single heartbeat. It's calculated from two volumes captured at opposite points in the cardiac cycle — End-Diastolic Volume (EDV), the amount of blood filling the ventricle right before it contracts (the fullest point), and End-Systolic Volume (ESV), the amount left behind right after it contracts (the emptiest point). The difference between these two — how much blood was actually pumped out — is the stroke volume. Stroke volume is one of the building blocks clinicians use to assess overall heart performance, since it feeds directly into other key cardiac metrics: multiplying stroke volume by heart rate gives cardiac output (total blood pumped per minute), and dividing stroke volume by EDV gives ejection fraction (the percentage of the ventricle's blood that gets pumped out each beat). A commonly cited normal resting stroke volume range for an average adult is roughly 60-100 mL, though this varies meaningfully with body size, fitness level, and heart rate. This calculator is for general reference and educational purposes only — it is not a medical diagnosis. Consult a doctor for actual cardiac function assessment.
How it works
Enter end-diastolic volume and end-systolic volume, both in milliliters, typically obtained from an echocardiogram, cardiac MRI, or nuclear imaging study. The tool subtracts end-systolic volume from end-diastolic volume (SV = EDV − ESV) to get the volume of blood ejected in a single heartbeat.
- Enter end-diastolic volume (mL).
- Enter end-systolic volume (mL).
- Click Calculate to see your results.
Examples
A typical resting value
With an EDV of 120 mL and an ESV of 50 mL: SV = 120 - 50 = 70 mL, within the commonly cited normal range.
A higher EDV with the same ESV
With an EDV of 140 mL and an ESV of 50 mL: SV = 140 - 50 = 90 mL — a larger filling volume translates directly into a larger stroke volume if emptying stays the same.
A reduced stroke volume
With an EDV of 100 mL and an ESV of 70 mL: SV = 100 - 70 = 30 mL — a lower stroke volume that could result from either reduced filling or impaired ejection, and would typically prompt further clinical evaluation.
Who should use it
- Reviewing echocardiogram or cardiac MRI volume data alongside a doctor.
- Feeding into other calculations like cardiac output or ejection fraction.
- Learning the relationship between EDV, ESV, and stroke volume in a physiology course.
Industry applications
- Cardiology reference
- Cardiac imaging education
Advantages
- Simple, transparent subtraction.
- Foundational formula used throughout cardiac physiology.
- Directly feeds into other key cardiac metrics like cardiac output and ejection fraction.
Limitations
- Requires already-measured ventricular volumes from imaging.
- A single snapshot value — trends over time are more clinically informative.
Common mistakes to avoid
- Mixing up end-diastolic volume (fullest) and end-systolic volume (emptiest).
- Using volumes measured under different physiological states (e.g. rest vs. exercise).
- Treating a single stroke volume reading as diagnostic on its own, without considering trends or other cardiac metrics.
Best practices
- Use EDV and ESV from the same imaging study for a consistent stroke volume value.
- Consider stroke volume alongside heart rate, cardiac output, and ejection fraction for a fuller picture rather than in isolation.
- Discuss any concerning stroke volume result with a cardiologist rather than interpreting it independently.
Tips
- Use this alongside our Ejection Fraction and Cardiac Output calculators for a fuller picture of cardiac performance.
- Track stroke volume trends over multiple visits rather than relying on one isolated measurement.