Blood Test Unit Converter
Instantly convert your test results between conventional units (mg/dL, g/L) and SI units (mmol/L, µmol/L). Type a value and the other units are calculated automatically.
Type a value in any unit: the others convert automatically.
Understand what “Blood glucose” measuresConventional or SI units: why two systems?
The same result can be expressed two ways. Conventional units measure a mass per volume — glucose in mg/dL in the United States, or in g/L in France. SI units measure an amount of substance — glucose in mmol/L. Neither is “better”: it depends on your lab's convention.
Converting lets you compare a result to a reference given in another unit, or line up two reports. Always compare your value to the reference interval printed on your own report, in the same unit.
The most common conversions
| Marker | Conversion |
|---|---|
| Glucose | 1 mmol/L = 18 mg/dL · 100 mg/dL = 5.55 mmol/L |
| Cholesterol | 1 mmol/L = 38.67 mg/dL · 200 mg/dL ≈ 5.2 mmol/L |
| Creatinine | 1 mg/dL = 88.4 µmol/L · 88 µmol/L = 1.0 mg/dL |
| A1C | 6% ≈ 42 mmol/mol · 7% ≈ 53 mmol/mol |
| Vitamin D | 1 ng/mL = 2.5 nmol/L |
Frequently asked questions
How do I convert glucose from mg/dL to mmol/L?
Divide the mg/dL value by 18. So 90 mg/dL ≈ 5.0 mmol/L; to go the other way, multiply mmol/L by 18 (5 mmol/L ≈ 90 mg/dL).
How do I convert cholesterol from mg/dL to mmol/L?
Divide mg/dL by 38.67 (1 mmol/L ≈ 38.67 mg/dL). For example, a total cholesterol of 200 mg/dL is about 5.2 mmol/L. The same conversion applies to LDL and HDL.
How do I convert creatinine from mg/dL to µmol/L?
Multiply mg/dL by 88.4 (1 mg/dL = 88.4 µmol/L). For example, 1.0 mg/dL ≈ 88 µmol/L. This helps you compare a U.S. report (mg/dL) with an international one (µmol/L).
How do I convert A1C from % to mmol/mol?
The relationship is not a simple ratio but affine: mmol/mol = (% − 2.15) × 10.929. So 6% ≈ 42 mmol/mol and 7% ≈ 53 mmol/mol. The converter does it automatically.
What is the difference between conventional and SI units?
Conventional units (mg/dL, g/L) express a mass per volume; SI units (mmol/L, µmol/L) express an amount of substance. Depending on the lab and country, your result is given in one or the other — which is why converting helps you compare.
Why is my result in a different unit than the reference shown?
Because labs do not all use the same convention. Always compare your value to the reference interval printed on your own report, in the same unit as your result.
Do these conversions replace a doctor’s advice?
No. This tool converts units for information only. Interpreting a result depends on your lab’s reference interval and your context; that belongs to your clinician.
Disclaimer. This tool uses standard conversion factors, for information only. It does not diagnose anything and does not replace the advice of a healthcare professional. Always check your results and their interpretation with your clinician or your lab.
Sources & method
The conversion factors are standard constants derived from each substance's molar mass. The A1C conversion (% NGSP ↔ mmol/mol IFCC) follows the official international standardization equation.
- 1
NGSP — “HbA1c Conversion (NGSP % ↔ IFCC mmol/mol)”, National Glycohemoglobin Standardization Program. · ngsp.org
- 2
Weykamp C, John WG, Mosca A. — “A review of the challenge in measuring hemoglobin A1c.” J Diabetes Sci Technol, 2009. · PubMed · DOI
To understand what each marker measures, see our marker guides, the reference-range table, or the eGFR calculator.