LDL cholesterol (Friedewald)

FREE

Calculated LDL from total cholesterol, HDL and triglycerides.

Note

LDL = 200 − 50 − 150/5 = 120 mg/dL (3.1 mmol/L).

Reference: Friedewald WT et al., Clin Chem 1972. For learning only. Reference intervals vary by laboratory, method and patient group; results are interpreted by qualified professionals with the clinical picture.

Formula

LDL = total cholesterol − HDL − triglycerides / 5 (all mg/dL)

Worked example

TC 200, HDL 50, TG 150 → LDL 120 mg/dL

Limitations

Not valid above 400 mg/dL triglycerides and less accurate at low LDL or non-fasting samples; many labs use the Martin–Hopkins or Sampson equation or direct LDL.

For learning only. Reference intervals vary by laboratory, method and patient group; results are interpreted by qualified professionals with the clinical picture.