LDL Cholesterol Unit Converter

In short LDL Cholesterol is reported in mg/dL in some countries and mmol/L in others, and the two are related by a fixed factor: 1 mg/dL = 0.0258629 mmol/L, so to go the other way you divide by 38.6654. 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 is not arbitrary — it comes from the molar mass, because cholesterol has a molar mass of 386.65 g/mol, and LDL measures the same molecule, and that is why every analyte has its own factor rather than one shared conversion. 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.