Stroke Volume Calculator
Calculate stroke volume from cardiac output and heart rate, or from end-diastolic and end-systolic volumes. Stroke Volume = EDV - ESV. Find ejection fraction and forward stroke volume.
❤️ Physiology📐 SV = EDV - ESV🧬 Biology
Method
EDV (mL) or CO (L/min)
ESV (mL) or HR (bpm)
Please enter valid values.
Formula & Reference
| Variable | Symbol | Formula | Units |
|---|---|---|---|
| Stroke Volume Calculator | — | SV = EDV - ESV | mL |
Step-by-Step Examples
Example 1
Echocardiography
EDV=120mL, ESV=50mL.
- SV = 120-50 = 70 mL
- EF = 70/120 x 100 = 58.3%
- Normal EF — good systolic function
✓ SV=70mL, EF=58.3%
Example 2
From CO/HR
CO=5 L/min, HR=70bpm.
- SV = 5000/70 = 71.4 mL
- Normal resting stroke volume
- Consistent with echo-derived value
✓ SV = 71 mL
Example 3
Heart Failure
EDV=200mL, ESV=150mL.
- SV = 200-150 = 50 mL
- EF = 50/200 = 25%
- Severely reduced EF — systolic heart failure
- Normal EDV but poor emptying
✓ SV=50mL, EF=25% (heart failure
Real-World Applications
Echocardiography
SV and EF are primary outputs of cardiac echo assessment.
Critical Care
SV monitoring guides fluid resuscitation in shock states.
Exercise Physiology
SV increases with aerobic training (athlete's heart adaptation).
Clinical Trials
SV response to heart failure therapies is a key endpoint.
Common Mistakes to Avoid
⚠️
Confusing SV with EF
EF measures pumping efficiency (SV/EDV x 100%). SV is absolute volume. A dilated heart can have normal SV but low EF.
⚠️
Using CO method without accurate HR
Heart rate must be accurate (not AF). In arrhythmias, use direct echo method instead.
⚠️
Ignoring valvular regurgitation
In mitral/aortic regurgitation, echo-derived SV includes regurgitant volume. Forward stroke volume is less than echo SV.
Frequently Asked Questions
What is ejection fraction? ▾
EF = SV/EDV x 100. Normal 55-70%. HFrEF (reduced EF): < 40%. HFpEF (preserved EF): > 50% with symptoms.
What is preload? ▾
Volume of blood in ventricle at end of diastole (EDV). Preload stretch increases contractility (Frank-Starling). Increased by volume overload, high venous return.
What is afterload? ▾
Resistance against which the heart pumps (systemic vascular resistance). High afterload (hypertension) reduces SV. Reduced by vasodilators.
How does training affect stroke volume? ▾
Regular aerobic exercise increases EDV (cardiac remodeling), increases SV at rest and exercise. Elite athletes SV 150-200mL vs 70mL in untrained.
What is heart failure with preserved EF? ▾
HFpEF: normal EF but impaired diastolic filling. EDV is normal or low, SV normal, but symptoms of heart failure from impaired relaxation. Harder to treat than HFrEF.