LDL Cholesterol (Friedewald) Calculator

About this calculator

The Friedewald equation estimates LDL cholesterol without a direct lab assay by subtracting HDL and an estimated VLDL (triglycerides divided by 5 in mg/dL, or by 2.2 in mmol/L) from total cholesterol. It was published in 1972 and remains the formula printed on most standard lipid panels because direct LDL measurement is more expensive and not routinely ordered.

Physicians, cardiologists and patients reviewing a routine cholesterol panel use this calculation to classify cardiovascular risk and decide on statin therapy, since LDL — not total cholesterol — is the primary target of most lipid-lowering guidelines. The equation’s known weakness is at high triglycerides: above roughly 400 mg/dL (4.5 mmol/L) the VLDL estimate breaks down and a direct LDL measurement or the Martin-Hopkins method is recommended instead.

This calculator takes your total cholesterol, HDL and triglycerides and returns the Friedewald-estimated LDL, flagging when triglycerides are too high for the formula to be reliable.