Friedewald Equation Calculator

The Friedewald equation is used to estimate low-density lipoprotein (LDL) cholesterol, commonly known as "bad" cholesterol, which is a key factor in assessing cardiovascular risk. This calculation is based on three primary measurements: total cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides.

Friedewald Equation Formula

The equation is:

\[ \text{LDL (mg/dL)} = \text{Total Cholesterol} - \text{HDL} - \frac{\text{Triglycerides}}{5} \]

Example Calculation

If your total cholesterol is 200 mg/dL, HDL is 50 mg/dL, and triglycerides are 150 mg/dL, the calculation would be:

\[ \text{LDL} = 200 - 50 - \frac{150}{5} = 200 - 50 - 30 = 120 \text{ mg/dL} \]

Usage and Limitations

This equation is widely used in clinical settings for quick LDL estimation, but it is not accurate for people with triglyceride levels above 400 mg/dL or very low LDL levels. In such cases, direct LDL measurement methods are recommended.

Common FAQs

1. Why is LDL important?

   • LDL cholesterol is associated with an increased risk of heart disease because it can lead to plaque buildup in arteries.

2. What does a high LDL level indicate?

   • Elevated LDL levels are a significant risk factor for atherosclerosis and cardiovascular events such as heart attacks and strokes.

3. When should the Friedewald equation not be used?

   • This formula is less accurate when triglyceride levels are very high (above 400 mg/dL) or in cases of low LDL levels, requiring more precise laboratory measurements.