Enter the total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) into the calculator to estimate low-density lipoprotein cholesterol (LDL-C) using the Friedewald equation (mg/dL units).

Estimated LDL Cholesterol (Friedewald) Calculator

Enter any 3 values to calculate the missing variable

Estimated LDL Cholesterol Formula (Friedewald Equation)

The following formula is used to estimate LDL cholesterol (LDL-C) in mg/dL using total cholesterol, HDL cholesterol, and triglycerides (Friedewald equation). Note: this estimation is generally considered unreliable when triglycerides are very high (commonly ≥ 400 mg/dL) or in certain dyslipidemias.

LDL = TC - HDL - (TG / 5)

Variables:

  • LDL is the estimated 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-C (mg/dL), subtract the HDL cholesterol from the total cholesterol, then subtract one-fifth of the triglycerides (TG/5). The TG/5 term is a common approximation for VLDL cholesterol in mg/dL used in the Friedewald equation.

What is LDL Cholesterol (Estimated)?

LDL cholesterol (LDL-C) is often called “bad” cholesterol because higher LDL-C levels are associated with a higher risk of atherosclerotic cardiovascular disease. LDL-C can be measured directly by a laboratory test, or it can be estimated from a standard lipid panel using the Friedewald equation (TC, HDL-C, and TG) when reported in mg/dL. Because it is an estimate, it may be inaccurate for very high triglycerides (commonly ≥ 400 mg/dL), non-fasting samples, or certain lipid disorders.

How to Calculate Estimated LDL Cholesterol?

The following steps outline how to estimate LDL cholesterol (LDL-C) using the Friedewald equation (mg/dL).

  1. First, determine the total cholesterol (TC) in mg/dL.
  2. Next, determine the HDL cholesterol (HDL-C) in mg/dL.
  3. Next, determine the triglycerides (TG) in mg/dL.
  4. Next, use the formula LDL = TC − HDL − (TG / 5) to estimate LDL cholesterol.
  5. Finally, calculate LDL-C using the obtained values for TC, HDL, and TG.

Example Problem:

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

Total cholesterol (TC) = 200 mg/dL

HDL cholesterol (HDL-C) = 50 mg/dL

Triglycerides (TG) = 150 mg/dL

Estimated LDL cholesterol (LDL-C) = 200 − 50 − (150 / 5) = 200 − 50 − 30 = 120 mg/dL