Enter the total cholesterol, HDL cholesterol, and triglycerides into the calculator to estimate the LDL cholesterol level using the Friedewald equation.

Friedewald Equation Formula

The Friedewald equation is used to estimate the level of LDL cholesterol in the blood when it is not directly measured. The formula is as follows:

LDL = TC - HDL - (TG / 5)


  • LDL is the low-density lipoprotein cholesterol (mg/dL)
  • TC is the total cholesterol (mg/dL)
  • HDL is the high-density lipoprotein cholesterol (mg/dL)
  • TG is the triglycerides (mg/dL)

To estimate LDL cholesterol, subtract the HDL cholesterol and one-fifth of the triglycerides level from the total cholesterol.

What is LDL Cholesterol?

LDL cholesterol, often referred to as “bad” cholesterol, is a type of lipoprotein that carries cholesterol through the bloodstream. High levels of LDL cholesterol can lead to plaque buildup in arteries, increasing the risk of heart disease and stroke. The Friedewald equation provides a way to estimate LDL levels when direct measurement is not available, which is particularly useful in routine health screenings.

How to Calculate LDL Cholesterol?

The following steps outline how to estimate LDL cholesterol using the Friedewald equation.

  1. First, determine the total cholesterol (TC) in milligrams per deciliter (mg/dL).
  2. Next, determine the HDL cholesterol (HDL) in mg/dL.
  3. Then, determine the triglycerides (TG) in mg/dL.
  4. Use the Friedewald equation: LDL = TC – HDL – (TG / 5).
  5. Finally, calculate the estimated LDL cholesterol (LDL) in mg/dL.
  6. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Total Cholesterol (TC) = 200 mg/dL

HDL Cholesterol (HDL) = 50 mg/dL

Triglycerides (TG) = 150 mg/dL