Convert cholesterol and triglyceride values between mg/dL and mmol/L. Full lipid panel conversion with risk assessment and reference ranges.
Cholesterol levels are reported in different units depending on the country: the United States uses mg/dL (milligrams per deciliter), while most other countries and the international scientific community use mmol/L (millimoles per liter). This difference causes constant confusion for patients comparing results across healthcare systems, reading international guidelines, or discussing values with providers trained in different measurement traditions.
This Cholesterol Unit Converter handles both individual value conversion and full lipid panel analysis. For cholesterol fractions (total, LDL, HDL, VLDL), the conversion factor is 38.67 (based on cholesterol's molecular weight of 386.7 g/mol). For triglycerides, the factor is 88.57 (average molecular weight ~885.7 g/mol). These are distinct factors — a common error is applying the cholesterol factor to triglycerides, which produces incorrect results.
Beyond simple unit conversion, the calculator assesses each value against ATP III and ACC/AHA reference ranges, calculates derived risk markers like the TC/HDL ratio and non-HDL cholesterol, and can estimate LDL via the Friedewald equation when only total cholesterol, HDL, and triglycerides are available. This makes it a comprehensive lipid panel interpretation tool, not just a unit converter.
International travel, immigration, telemedicine, and access to global medical literature all create situations where cholesterol unit conversion is needed. This tool eliminates conversion math errors, applies the correct factors for cholesterol versus triglycerides, and adds clinical context through risk classification and derived metrics. Keep these notes focused on your operational context. Tie the context to the calculator’s intended domain.
Cholesterol (mmol/L) = Cholesterol (mg/dL) ÷ 38.67. Triglycerides (mmol/L) = Triglycerides (mg/dL) ÷ 88.57. Non-HDL = Total Cholesterol − HDL. TC/HDL Ratio = Total Cholesterol ÷ HDL. Friedewald LDL = Total − HDL − (Triglycerides / 5) [valid when TG < 400 mg/dL].
Result: Total: 5.69 mmol/L, LDL: 3.62 mmol/L, HDL: 1.29 mmol/L, TG: 2.03 mmol/L
Total: 220 ÷ 38.67 = 5.69 mmol/L (borderline high). LDL: 140 ÷ 38.67 = 3.62 mmol/L (borderline high). HDL: 50 ÷ 38.67 = 1.29 mmol/L (acceptable). Triglycerides: 180 ÷ 88.57 = 2.03 mmol/L (borderline high).
The conversion factor derives from molecular weight: cholesterol has a molecular weight of 386.7 g/mol. To convert from mass concentration (mg/dL) to molar concentration (mmol/L), divide by (molecular weight / 10) = 38.67. Triglycerides are a heterogeneous mix of molecules, but the average molecular weight used for conversion is 885.7 g/mol, giving a factor of 88.57.
The European Society of Cardiology (ESC) uses mmol/L exclusively, targeting LDL < 1.4 mmol/L (54 mg/dL) for very high-risk patients. The American College of Cardiology (ACC) uses mg/dL, with the same target expressed as LDL < 55 mg/dL. Understanding both systems is essential for interpreting international cardiovascular guidelines and clinical trial results.
Beyond the standard lipid panel, advanced testing can measure LDL particle number (LDL-P), apolipoprotein B, lipoprotein(a), and LDL particle size. These tests provide additional cardiovascular risk information and are reported in various units. While this calculator focuses on the standard panel, awareness of advanced markers helps clinicians identify residual risk in patients with "normal" standard panels.
The US medical system historically adopted mass concentration units (mg/dL), while the international SI system uses molar concentration (mmol/L). Neither is inherently better, but the international system has the advantage of being based on the number of molecules rather than mass.
Yes — total cholesterol, LDL, HDL, and VLDL all use the same conversion factor of 38.67 because they all measure the same molecule (cholesterol) with the same molecular weight. Only triglycerides use a different factor (88.57) due to their different molecular weight.
The American Heart Association considers a TC/HDL ratio below 5.0 as desirable. Optimal is below 3.5. The ratio is a strong predictor of cardiovascular disease — a ratio above 5.0 indicates approximately double the average heart disease risk.
Non-HDL cholesterol (total minus HDL) captures all "bad" cholesterol particles including LDL, VLDL, IDL, and Lp(a). Some guidelines consider non-HDL a better predictor of cardiovascular risk than LDL alone because it represents all atherogenic lipoproteins.
The Friedewald equation (LDL = Total − HDL − TG/5) is inaccurate when triglycerides exceed 400 mg/dL (4.52 mmol/L), in non-fasting samples, or in patients with type III hyperlipoproteinemia. In these cases, direct LDL measurement is needed.
Current ACC/AHA guidelines accept non-fasting lipid panels for initial screening. However, if triglycerides are elevated (>400 mg/dL) or if LDL needs to be calculated via Friedewald, a 9–12 hour fasting sample is recommended for accuracy.