LDL Cholesterol — mmol/L to mg/dL

In short To convert LDL cholesterol from mmol/L to mg/dL, multiply by 38.6654 — so one mmol/L is 38.6654 mg/dL, and one mg/dL is 0.0258629 mmol/L. 70 mg/dL is 1.8 mmol/L; 100 mg/dL is 2.6 mmol/L; 130 mg/dL is 3.4 mmol/L. The factor comes from the molar mass, because cholesterol has a molar mass of 386.65 g/mol, and LDL measures the same molecule; that is why it differs for every analyte and why a single "lab unit converter" factor does not exist. LDL is often not measured at all but calculated from the other three lipids by the Friedewald equation, and that equation is written for one unit system at a time — its constant is triglycerides ÷ 5 in mg/dL and triglycerides ÷ 2.2 in mmol/L. Mixing units inside it is a classic and invisible error, which is a good reason to convert the finished LDL figure rather than the inputs. This converts units. It does not interpret results, does not compare your value against a reference interval, and is not a substitute for the clinician who ordered the test — reference intervals differ between laboratories, methods and populations.