Gorlin Valve-Area Equation
Gorlin valve-area equation for aortic or mitral stenosis: flow ÷ (constant × √mean gradient), using the systolic ejection period (aortic) or diastolic filling period (mitral).
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Valve
- Aortic (systolic ejection period, K = 44.3)
- Cardiac output
- 5 L/min
- Heart rate
- 70 bpm
- Ejection/filling period
- 0.33 s per beat
- Mean pressure gradient
- 40 mmHg
Result: Valve area 0.77 cm² (flow 216.5 mL/s) — severe aortic stenosis.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Severity
- Valve area (cm²): severe < 1.0, moderate 1.0–1.5, mild > 1.5.
What you enter
- Valve
- Cardiac output
- Heart rate
- Ejection/filling period
- Mean pressure gradient
How this is calculated
- Formula
- Area = flow / (K·√mean gradient); flow = CO(mL/min) / (period·HR). K = 44.3 aortic (SEP), 37.7 mitral (DFP).
Gorlin R, Gorlin SG. Hydraulic formula for the calculation of the area of the stenotic mitral valve, other cardiac valves, and central circulatory shunts. Am Heart J. 1951;41(1):1-29. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.