Blood Sugar Converter
Convert blood sugar readings between mg/dL and mmol/L units instantly. See whether your glucose level falls in the normal, pre-diabetic, or diabetic range for fasting, post-meal, and A1C readings.
How the Blood Sugar Converter Works
A blood sugar converter is a tool that translates glucose readings between the two standard measurement units used worldwide: mg/dL (milligrams per deciliter), used primarily in the United States, and mmol/L (millimoles per liter), used in the United Kingdom, Canada, Australia, and most other countries. The conversion formula is straightforward: divide mg/dL by 18.0182 to get mmol/L, or multiply mmol/L by 18.0182 to get mg/dL. This converter also evaluates your reading against clinical thresholds established by the American Diabetes Association to determine whether your level is normal, indicates pre-diabetes, or falls in the diabetic range.
Blood Sugar Ranges by Reading Type
Blood sugar ranges differ depending on when the reading was taken. For fasting glucose (no food for 8+ hours), normal is below 100 mg/dL (5.6 mmol/L), pre-diabetic is 100-125 mg/dL (5.6-6.9 mmol/L), and diabetic is 126 mg/dL (7.0 mmol/L) or higher. For a 2-hour post-meal reading, normal is below 140 mg/dL (7.8 mmol/L), pre-diabetic is 140-199 mg/dL (7.8-11.0 mmol/L), and diabetic is 200 mg/dL (11.1 mmol/L) or above. Random glucose readings of 200 mg/dL or higher with symptoms suggest diabetes. For A1C, normal is below 5.7%, pre-diabetic is 5.7-6.4%, and diabetic is 6.5% or higher. Based on 2026 American Diabetes Association guidelines.
Understanding mg/dL vs mmol/L
The two units measure the same thing differently. Milligrams per deciliter (mg/dL) measures the weight of glucose in a specific volume of blood and is the standard in the United States, Japan, and several other countries. Millimoles per liter (mmol/L) measures the number of glucose molecules in a volume of blood and is used by most of the world including Europe, Canada, and Australia. If you travel internationally, share results with a doctor in another country, or read medical research published abroad, converting between these units is essential for accurate comparison. The conversion factor of 18.0182 comes from the molecular weight of glucose (180.16 g/mol) divided by 10.
A1C and Estimated Average Glucose
The A1C test measures the percentage of hemoglobin in your blood that has glucose attached, reflecting your average blood sugar over the past 2-3 months. Unlike spot checks, A1C gives a long-term picture of glucose control. The formula to convert A1C to estimated average glucose (eAG) is: eAG in mg/dL = (A1C x 28.7) - 46.7. For example, an A1C of 7.0% corresponds to an average glucose of approximately 154 mg/dL (8.6 mmol/L). This converter handles A1C readings and shows both the equivalent average glucose and the clinical assessment of your result.
Frequently Asked Questions
What is the conversion factor between mg/dL and mmol/L?
Divide mg/dL by 18.0182 to get mmol/L, or multiply mmol/L by 18.0182 to get mg/dL. This factor comes from the molecular weight of glucose (180.16 g/mol).
What is a normal fasting blood sugar level?
A normal fasting blood sugar is below 100 mg/dL (5.6 mmol/L). Readings between 100-125 mg/dL (5.6-6.9 mmol/L) indicate pre-diabetes, and 126 mg/dL (7.0 mmol/L) or higher indicates diabetes.
What blood sugar level is considered diabetic after eating?
A 2-hour post-meal blood sugar of 200 mg/dL (11.1 mmol/L) or higher indicates diabetes. Between 140-199 mg/dL (7.8-11.0 mmol/L) is pre-diabetic. Below 140 mg/dL (7.8 mmol/L) is normal.
How is A1C converted to average blood sugar?
The formula is eAG (mg/dL) = (A1C x 28.7) - 46.7. For example, an A1C of 6.5% equals approximately 140 mg/dL average blood sugar. Divide by 18.0182 to convert to mmol/L.
Why do some countries use mg/dL and others use mmol/L?
The US, Japan, and some other countries use mg/dL (mass concentration). Most of the world including Europe, Canada, and Australia uses mmol/L (molar concentration). Both measure glucose but with different scales.
Is this tool a substitute for medical advice?
No. This converter provides general reference ranges based on American Diabetes Association guidelines. Always consult your healthcare provider for diagnosis, treatment decisions, and personalized blood sugar targets.