LDL Cholesterol Calculator

About this calculator

This calculator uses the Friedewald equation, the formula labs have used for decades to estimate "bad" cholesterol without directly measuring it: LDL = Total Cholesterol − HDL − (Triglycerides ÷ 5), all in mg/dL (the divisor is 2.2 when working in mmol/L). It works because VLDL cholesterol — the third major lipoprotein — is roughly one-fifth of the triglyceride level in a fasting sample, so subtracting that estimate along with HDL isolates LDL.

It's the calculation behind most standard lipid panel reports and is what your doctor is reading when discussing "LDL" from routine bloodwork. The formula becomes unreliable and is not reported when triglycerides exceed 400 mg/dL, since the VLDL approximation breaks down — in that case labs switch to direct LDL measurement or the newer Martin-Hopkins method instead.