How to use this tool
- Pick the test from the list.
- Choose the direction: conventional (US) units to SI, or the reverse.
- Enter the value from your report and read the converted result.
Why lab units differ
Most of the world adopted the International System of Units (SI) for lab reports, which counts substances in moles (mmol/L, µmol/L). The United States mostly kept "conventional" units by mass (mg/dL, g/dL). Laboratories in India and Pakistan commonly use conventional units, while UK reports use SI. If you move between countries, or read guidelines from abroad, the numbers can look alarmingly different for the same result.
Examples
A total cholesterol of 200 mg/dL is 5.2 mmol/L. Creatinine of 1.0 mg/dL is 88 µmol/L. Vitamin D of 30 ng/mL is 75 nmol/L. Note that the BUN conversion gives urea in mmol/L because urea nitrogen and urea are counted per mole of urea.
Reference ranges
Reference ranges vary between laboratories, methods, age and sex. Always compare a result with the range printed on your own report and discuss it with a clinician.
Frequently asked questions
How do I convert cholesterol mg/dL to mmol/L?
Divide by 38.67, or multiply by 0.02586. 200 mg/dL is 5.17 mmol/L.
How do I convert creatinine µmol/L to mg/dL?
Divide by 88.4. 106 µmol/L is 1.2 mg/dL.
How do I convert vitamin D nmol/L to ng/mL?
Divide by 2.496. 50 nmol/L is about 20 ng/mL.
How do I convert triglycerides mmol/L to mg/dL?
Multiply by 88.57. 1.7 mmol/L is about 150 mg/dL.
Sources and references
- AMA Manual of Style: SI conversion factors for laboratory values
- Young DS. Implementation of SI units for clinical laboratory data. Ann Intern Med 1987;106:114–29