Blood glucose (blood sugar) can be measured in two different units: mg/dL (milligrams per deciliter), commonly used in the United States, and mmol/L (millimoles per liter), the international SI standard used in most other countries. This converter allows quick and accurate conversion between these two units, which is essential for patients traveling internationally, comparing lab results from different countries, or reading medical literature that uses a different unit system.
To convert from mg/dL to mmol/L, divide by 18.0182 (the molecular weight of glucose divided by 10). To convert from mmol/L to mg/dL, multiply by 18.0182. For example, a fasting glucose of 100 mg/dL equals approximately 5.6 mmol/L. You can also check your long-term glucose control using our HbA1c calculator.
This conversion is mathematically exact and applies only to glucose. Other substances (such as cholesterol or triglycerides) use different conversion factors. The converted value does not change the clinical interpretation, which depends on the reference ranges provided by the specific laboratory.
FAQ
Why are there two different units for blood sugar?
The mg/dL unit (conventional) measures mass concentration and is standard in the US, Japan, and some other countries. The mmol/L unit (SI) measures molar concentration and is used in most of Europe, Canada, Australia, and many other countries. Both are equally valid for clinical purposes.
What are normal blood sugar levels in both units?
Normal fasting blood sugar is 70-99 mg/dL (3.9-5.5 mmol/L). Prediabetes range is 100-125 mg/dL (5.6-6.9 mmol/L). Diabetes is diagnosed at 126 mg/dL (7.0 mmol/L) or higher on two separate occasions. For long-term monitoring, consider using our HbA1c calculator.
Can I use this conversion for other blood tests?
No, this conversion factor (18.0182) is specific to glucose. Other substances like cholesterol use different conversion factors (38.67 for cholesterol, 88.57 for triglycerides). Use our cholesterol converter for lipid panel conversions.