Convert common lab values between conventional (US) and SI (international) units. Covers glucose, cholesterol, hemoglobin, creatinine, and 20+ lab tests.
The Medical Unit Converter translates laboratory values between conventional (US) units and SI (Système International) units used in most other countries. If you've had blood work done abroad, received results from an international laboratory, or are reading medical literature, you'll encounter different unit systems for the same test. A glucose of 100 mg/dL (US) equals 5.6 mmol/L (SI) — the same reading, expressed differently.
This converter covers 20+ commonly ordered lab tests including glucose, cholesterol (total, LDL, HDL, triglycerides), hemoglobin, creatinine, urea/BUN, electrolytes (sodium, potassium, calcium, magnesium), liver enzymes, thyroid function tests, and more. Each conversion uses the standard molecular weight and conversion factor recognized by clinical laboratories worldwide.
The tool also displays normal reference ranges in both unit systems so you can quickly assess whether a result is within the expected range. Whether you are a beginner or experienced professional, this free online tool provides instant, reliable results without manual computation.
Different countries use different unit systems for laboratory results. The US primarily uses conventional units (mg/dL, g/dL), while most of the world uses SI units (mmol/L, g/L). Medical literature, international guidelines, and health apps may report values in either system. This converter eliminates confusion and reduces the risk of misinterpreting lab results when comparing across systems.
SI Value = Conventional Value × Conversion Factor Conventional Value = SI Value / Conversion Factor Common Conversion Factors: • Glucose: 1 mg/dL = 0.0555 mmol/L (factor: 0.0555) • Total Cholesterol: 1 mg/dL = 0.0259 mmol/L • Triglycerides: 1 mg/dL = 0.0113 mmol/L • Creatinine: 1 mg/dL = 88.4 µmol/L • BUN: 1 mg/dL = 0.357 mmol/L • Hemoglobin: 1 g/dL = 10 g/L • Calcium: 1 mg/dL = 0.25 mmol/L • Sodium/Potassium: mEq/L = mmol/L (1:1)
Result: 7.0 mmol/L
Glucose at 126 mg/dL is converted by multiplying by the factor 0.05551: 126 × 0.05551 = 6.99 ≈ 7.0 mmol/L. This value is above the fasting glucose threshold of 7.0 mmol/L (126 mg/dL) used to diagnose diabetes. The result and interpretation are identical regardless of which unit system is used.
Clinical chemistry initially reported results in mass units because weighing was the primary analytical technique. As molecular biology advanced, the mole-based SI system was proposed for medical use in 1967 by the International Federation of Clinical Chemistry. Most countries adopted SI units by the 1980s, but the US, UK (partially), and a few others retained conventional units. The dual-system reality creates an ongoing risk of unit-related errors in international medicine.
Home glucose meters in the US display mg/dL, while those sold in Europe display mmol/L. Travelers with diabetes must be aware of this difference. Some meters can switch between units in settings. If using a meter purchased abroad, verify the unit before adjusting insulin doses. An accidental interpretation of 7.0 mmol/L (normal) as 7.0 mg/dL (impossible, would mean near-zero glucose) could be dangerous.
The World Health Organization and International Federation of Clinical Chemistry continue to advocate for universal SI unit adoption. The American Medical Association has encouraged the transition, but surveys show most US physicians prefer conventional units. Electronic health records increasingly support dual-unit display, which may eventually facilitate a gradual transition.
The US adopted mass-based reporting (mg/dL) early in clinical chemistry history. Most other countries later adopted SI units (mmol/L), which report molar concentrations reflecting the number of molecules rather than mass. SI units are considered more scientifically rigorous because they allow direct comparison of molar ratios between different substances. The US has been slow to transition due to the enormous cost of retraining and updating systems.
Reference ranges may vary slightly between labs even within the same country due to differences in equipment, reagents, and testing methodologies. The numeric thresholds for disease diagnosis (e.g., fasting glucose ≥ 126 mg/dL or ≥ 7.0 mmol/L for diabetes) are standardized internationally but are expressed in different units. Always use the reference range printed on YOUR lab report.
Conversion factors depend on molecular weight. Cholesterol has a molecular weight of ~386.65 g/mol, giving a factor of 0.02586. Triglycerides are a mixture of molecules with an average molecular weight of ~885 g/mol, giving a factor of 0.01129. Since the molecular weights differ, the conversion factors are different even though both are measured in mg/dL in conventional units.
mEq/L (milliequivalents per liter) measures the charge contributed by ions in solution. For monovalent ions like sodium (Na⁺), potassium (K⁺), and chloride (Cl⁻), 1 mEq = 1 mmol. For divalent ions like calcium (Ca²⁺) and magnesium (Mg²⁺), 1 mmol = 2 mEq because each ion carries two charges. This is why calcium conversion between US and international units requires careful attention.
Yes. The IFCC (international) reports HbA1c in mmol/mol, while the US uses the NGSP percentage. The conversion is: IFCC mmol/mol = (NGSP % − 2.15) × 10.929. For example, an HbA1c of 7.0% = 53 mmol/mol. Both represent the same level of glycemic control.
The conversion factors used are standard clinical chemistry factors recognized by international laboratory organizations. The mathematical conversion is exact. However, the precision of the original measurement (which depends on the lab's equipment and methodology) determines the clinical significance of the converted value. Report converted values to the same decimal precision as the original.