Ldl Calculation Equation

Friedewald Equation:

\[ LDL-C = TC - HDL-C - \frac{TG}{5} \]

LDL Cholesterol (LDL-C):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Friedewald Equation?

The Friedewald equation estimates LDL cholesterol (LDL-C) from total cholesterol, HDL cholesterol, and triglycerides. It is widely used in clinical practice as a cost-effective alternative to direct LDL measurement.

2. How Does the Calculator Work?

The calculator uses the Friedewald equation:

\[ LDL-C = TC - HDL-C - \frac{TG}{5} \]

Where:

\( TC \) — Total cholesterol (mg/dL)
\( HDL-C \) — HDL cholesterol (mg/dL)
\( TG \) — Triglycerides (mg/dL)

Explanation: The equation estimates LDL cholesterol by subtracting HDL cholesterol and VLDL cholesterol (estimated as TG/5) from total cholesterol.

3. Importance of LDL Calculation

Details: LDL cholesterol is a major risk factor for cardiovascular disease. Accurate estimation helps in assessing cardiovascular risk and guiding lipid-lowering therapy decisions.

4. Using the Calculator

Tips: Enter total cholesterol, HDL cholesterol, and triglycerides in mg/dL. All values must be valid and greater than 0. Note: This equation is not valid when triglycerides exceed 400 mg/dL.

5. Frequently Asked Questions (FAQ)

Q1: When is the Friedewald equation not accurate?
A: The equation is less accurate when triglycerides exceed 400 mg/dL, in non-fasting samples, or in patients with certain lipid disorders.

Q2: What are the limitations of this equation?
A: It underestimates LDL-C at low LDL levels and overestimates at high triglyceride levels. Direct LDL measurement is preferred in these cases.

Q3: What are optimal LDL cholesterol levels?
A: Generally, LDL-C below 100 mg/dL is optimal, below 70 mg/dL for high-risk patients, but targets should be individualized based on overall cardiovascular risk.

Q4: Can this equation be used with non-fasting samples?
A: The equation was designed for fasting samples. Non-fasting samples may yield inaccurate results due to elevated triglyceride levels.

Q5: Are there alternative equations for LDL estimation?
A: Yes, newer equations like the Martin-Hopkins equation may provide more accurate estimates, especially at low LDL and high triglyceride levels.