Calculates LDL, non-HDL cholesterol, and the L/H ratio using the Friedewald equation.
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Calculation basis and official references
Reviewed on:
This calculator is not a diagnosis, treatment plan, or prescription. Please consult a qualified clinician about your medical decisions.
Formula basis
LDL (mg/dL) = total cholesterol - HDL - triglycerides / 5. non-HDL (mg/dL) = total cholesterol - HDL. L/H ratio = LDL / HDL.
Calculation method
Estimates LDL cholesterol from total cholesterol, HDL cholesterol, and triglycerides using the Friedewald equation, and also reports non-HDL cholesterol and the L/H ratio (LDL divided by HDL).
Exclusions and checks required
When triglycerides reach 400 mg/dL or higher, the assumption behind the Friedewald equation (VLDL cholesterol is approximately triglycerides/5) breaks down and the estimate becomes unreliable, so this calculator does not compute a result in that case. Japan Atherosclerosis Society guidelines likewise recommend using non-HDL-C instead of LDL-C in this situation.
Using a non-fasting (random) triglyceride value can also increase the error of the Friedewald estimate.
This equation is a statistical approximation that assumes a fasting blood draw and may differ from LDL measured by a direct assay method.
Example input:：Example: total cholesterol 200, HDL 55, triglycerides 120 (mg/dL)
tc
200
hdl
55
tg
120
The LDL value is an estimate; decisions about lipid management require evaluation by a healthcare professional.
Who is this calculator for? LDL Cholesterol Estimation
Calculates LDL, non-HDL cholesterol, and the L/H ratio using the Friedewald equation.
What values should I enter?
Applies to: Lab values
How should I interpret this estimate?
Estimates LDL cholesterol from total cholesterol, HDL cholesterol, and triglycerides using the Friedewald equation, and also reports non-HDL cholesterol and the L/H ratio (LDL divided by HDL).
How to use
Enter your input values and press Calculate.
Review the result and compare it with expected context.
LDL (mg/dL) = total cholesterol - HDL - triglycerides / 5. non-HDL (mg/dL) = total cholesterol - HDL. L/H ratio = LDL / HDL.