Blood Test Unit Converter
Convert blood test results between conventional units (mg/dL, ng/dL) and SI units (mmol/L, nmol/L) for over 50 biomarkers. Select your biomarker, enter a value, and get an instant conversion.
How to Convert Blood Test Units
Blood test results can be reported in different measurement units depending on the country, laboratory, or healthcare system. The two main systems are conventional units (commonly used in the United States) and SI units (Système International, used in most other countries). This can make it confusing to compare results from different labs or understand values from international medical literature.
Why Do Different Countries Use Different Units?
The United States primarily uses conventional units such as mg/dL (milligrams per deciliter) and ng/dL (nanograms per deciliter). Most of Europe, Australia, Canada, and the rest of the world use SI units such as mmol/L (millimoles per liter) and nmol/L (nanomoles per liter). The SI system was adopted internationally in the 1970s to standardize scientific measurement, but the US medical system largely retained the older conventional system.
This means a glucose reading of 100 mg/dL in the US is the same as 5.55 mmol/L in Europe. Both values are identical — just expressed differently.
Common Blood Test Unit Conversions
| Biomarker | Conventional Unit | SI Unit | Multiply by |
|---|---|---|---|
| Glucose | mg/dL | mmol/L | 0.0555 |
| Total Cholesterol | mg/dL | mmol/L | 0.0259 |
| LDL Cholesterol | mg/dL | mmol/L | 0.0259 |
| HDL Cholesterol | mg/dL | mmol/L | 0.0259 |
| Triglycerides | mg/dL | mmol/L | 0.0113 |
| Creatinine | mg/dL | µmol/L | 88.4 |
| Uric Acid | mg/dL | µmol/L | 59.48 |
| Bilirubin (Total) | mg/dL | µmol/L | 17.1 |
| Testosterone | ng/dL | nmol/L | 0.0347 |
| Vitamin D (25-OH) | ng/mL | nmol/L | 2.496 |
| Vitamin B12 | pg/mL | pmol/L | 0.7378 |
| Iron | µg/dL | µmol/L | 0.1791 |
| Cortisol | µg/dL | nmol/L | 27.59 |
| Hemoglobin | g/dL | g/L | 10 |
How Unit Conversion Works
Each biomarker has a specific conversion factor based on its molecular weight. To convert from conventional units to SI units, you multiply by the conversion factor. To convert back, you divide by it. For example:
- Glucose: 100 mg/dL × 0.0555 = 5.55 mmol/L
- Total Cholesterol: 200 mg/dL × 0.0259 = 5.18 mmol/L
- Creatinine: 1.0 mg/dL × 88.4 = 88.4 µmol/L
- Testosterone: 500 ng/dL × 0.0347 = 17.35 nmol/L
Tips for Comparing Blood Test Results
- Always check the units printed on your lab report before comparing values with reference ranges or past results.
- When comparing results from different labs or countries, convert to the same unit system first.
- Some biomarkers (like HbA1c or TSH) use the same units worldwide, so no conversion is needed.
- If in doubt, ask your healthcare provider to clarify which units your results are in.
Track All Your Blood Work in One Place
Health3 automatically converts units, tracks your biomarkers over time, and shows you personalized optimal ranges — not just "normal" ones.
