About the Lab Unit Converter (mg/dL to mmol/L)
Blood test results are reported in conventional units (mg/dL, g/dL, ng/mL) in the United States and in SI units (mmol/L, µmol/L, g/L, nmol/L) in the UK, Europe, Canada, Australia and most of the world. This converter switches common lab values between the two in either direction, using conversion factors derived from each substance’s molar mass, so you can compare a result with a guideline or a previous test from another country.
It covers glucose, cholesterol (total, LDL, HDL and non-HDL all use the same factor), triglycerides, creatinine, blood urea nitrogen to urea, hemoglobin, albumin, 25-hydroxy vitamin D, calcium, magnesium, uric acid, bilirubin, and HbA1c between NGSP percent and IFCC mmol/mol. It is useful for patients reading overseas lab reports, travelling clinicians, medical students and researchers combining data sets.
Each conversion is exact arithmetic, but laboratories may round differently and reference ranges vary between labs and methods. Always interpret a result against the reference range printed on your own report.
With the default inputs, the converted value is 5.17. Change any value above to recalculate instantly.
How to use the lab unit converter (mg/dl to mmol/l)
- 1Choose the test you want to convert.
- 2Pick the direction: conventional (US) to SI, or SI to conventional.
- 3Enter the value from your lab report.
- 4Read the converted value and the factor used.
- 5Compare it with the reference range on your own report.
Formula and method
Converting mg/dL to mmol/L means changing mass per decilitre into moles per litre: multiply by 10 (decilitres per litre) and divide by the molar mass in g/mol. For cholesterol (386.7 g/mol) that gives 1 mmol/L = 38.67 mg/dL; for glucose (180.16 g/mol), 18.016 mg/dL; for creatinine (113.12 g/mol), 1 mg/dL = 88.4 µmol/L. Triglycerides are conventionally expressed as triolein (1 mmol/L = 88.57 mg/dL), and BUN converts to urea by dividing by 2.8, the mass of the two nitrogen atoms in a urea molecule.
Mass-to-mass conversions such as hemoglobin and albumin (g/dL to g/L) simply multiply by 10. HbA1c is not a simple ratio: the NGSP master equation, % = 0.09148 × mmol/mol + 2.152, links the DCCT-aligned percent with the IFCC reference method.
- factor
- Multiplier from conventional to SI units for the selected test
- molar mass
- Grams per mole of the measured substance (PubChem)
- NGSP %
- HbA1c in DCCT-aligned percent
- IFCC
- HbA1c in mmol per mol of hemoglobin
Worked examples
Total cholesterol 200 mg/dL to mmol/L
Dividing 200 mg/dL by 38.67 gives 5.17 mmol/L — the common "borderline high" threshold of 200 mg/dL is about 5.2 mmol/L.
Creatinine 110 µmol/L to mg/dL
Dividing 110 µmol/L by 88.4 gives about 1.24 mg/dL.
Vitamin D 20 ng/mL to nmol/L
Multiplying 20 ng/mL by 2.496 gives about 50 nmol/L, the level often used as the threshold for sufficiency.
HbA1c 7% to mmol/mol
Using the NGSP master equation, (7 − 2.152) ÷ 0.09148 = 53.0 mmol/mol.
Frequently asked questions
How do I convert cholesterol from mg/dL to mmol/L?+
Divide by 38.67. For example, 200 mg/dL ÷ 38.67 = 5.17 mmol/L. To go the other way, multiply mmol/L by 38.67. The same factor applies to total, LDL, HDL and non-HDL cholesterol.
How do I convert glucose from mmol/L to mg/dL?+
Multiply by 18 (18.016 exactly). A fasting glucose of 7.0 mmol/L equals about 126 mg/dL, the diagnostic threshold for diabetes.
Why is the triglyceride factor different from cholesterol?+
Each substance has a different molar mass. Triglycerides are expressed as triolein (molar mass about 885 g/mol), so by convention 1 mmol/L equals 88.57 mg/dL, versus 38.67 for cholesterol.
How do I convert creatinine from µmol/L to mg/dL?+
Divide by 88.4. A creatinine of 88 µmol/L is about 1.0 mg/dL. Many eGFR equations require mg/dL, so this conversion is common.
Is BUN the same as urea?+
No. BUN measures only the nitrogen in urea. To convert BUN in mg/dL to urea in mmol/L, divide by 2.8; to convert urea in mg/dL to mmol/L, divide by 6.006.
How do I convert vitamin D from nmol/L to ng/mL?+
Divide by 2.496 (or multiply by about 0.4). A level of 75 nmol/L equals about 30 ng/mL.
For healthcare professionals and education only. This calculator implements a published formula or score but is not a diagnosis and does not replace clinical judgment. Verify inputs and results against the original source before using them in patient care.