Tool 44/54·Charts & Guides
Convert blood glucose between mg/dL and mmol/L — with visual range indicators for normal, prediabetes, and diabetes zones.
Enter a value in either field — both update simultaneously.
Common values (mg/dL)
Conversion factor: 1 mmol/L = 18.0182 mg/dL (based on the molecular weight of glucose: 180.182 g/mol).
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Common blood glucose values with their mg/dL and mmol/L equivalents and clinical significance.
| mg/dL | mmol/L | Clinical Note | Zone |
|---|---|---|---|
| 40 | 2.2 | Severe hypoglycemia | Hypoglycemia |
| 55 | 3.1 | Low (symptomatic) | Hypoglycemia |
| 70 | 3.9 | Hypo threshold | Normal (Fasting) |
| 80 | 4.4 | Normal low | Normal (Fasting) |
| 90 | 5.0 | Optimal fasting | Normal (Fasting) |
| 100 | 5.5 | Prediabetes threshold | Prediabetes |
| 120 | 6.7 | Post-meal target | Prediabetes |
| 126 | 7.0 | Diabetes threshold | Diabetes |
| 140 | 7.8 | 2-hr post-meal limit | Diabetes |
| 180 | 10.0 | Post-meal high | Diabetes |
| 200 | 11.1 | Random diabetes mark | Diabetes |
| 270 | 15.0 | High hyperglycemia | Diabetes |
Blood glucose is measured in two units depending on where you live. In the United States, mg/dL (milligrams per deciliter) is standard. Most of Europe, Australia, and much of Asia use mmol/L (millimoles per liter). Both measure the same thing — the concentration of glucose in your blood — using different scales. The conversion factor is 18.0182, derived from the molecular weight of glucose (180.182 g/mol).
The Conversion Formula
mg/dL → mmol/L: divide by 18.0182 | mmol/L → mg/dL: multiply by 18.0182
Example: 126 mg/dL ÷ 18.0182 = 6.99 mmol/L (the diabetes diagnostic threshold).
The American Diabetes Association (ADA) and World Health Organization (WHO) use specific fasting plasma glucose thresholds for classification. A fasting glucose below 100 mg/dL (5.6 mmol/L) is normal. Between 100–125 mg/dL (5.6–6.9 mmol/L) is impaired fasting glucose — often called prediabetes. At or above 126 mg/dL (7.0 mmol/L) on two occasions confirms diabetes. Post-meal (2-hour) thresholds are slightly higher: normal below 140 mg/dL (7.8 mmol/L), prediabetes at 140–199 mg/dL (7.8–11.0 mmol/L), and diabetes at or above 200 mg/dL (11.1 mmol/L).
Consumer glucometers sold in the United States display mg/dL by default; devices sold in the UK, Europe, and Australia default to mmol/L. Many modern meters allow you to switch units in the settings menu. If you are comparing readings with someone using a device from a different country, or reading international research, this conversion chart ensures you are comparing equivalent values. Tracking your numbers alongside diet in an app like Caloria helps you spot patterns between meals and blood sugar responses over time.
Medical Disclaimer
This tool is for educational and reference purposes only. It does not constitute medical advice, diagnosis, or treatment. Blood sugar thresholds vary by context (fasting vs. post-meal, venous vs. capillary blood, individual factors). Always consult a qualified healthcare provider for interpretation of your blood glucose results.
01
mg/dL (milligrams per deciliter) and mmol/L (millimoles per liter) are two units for measuring blood glucose concentration. The United States, Canada (for some tests), and several other countries use mg/dL. Most of Europe, Australia, and much of Asia use mmol/L. To convert mg/dL to mmol/L, divide by 18.0182. To go the other way, multiply mmol/L by 18.0182.
02
A normal fasting blood glucose is below 100 mg/dL (5.6 mmol/L). A reading between 100–125 mg/dL (5.6–6.9 mmol/L) indicates prediabetes. A fasting reading of 126 mg/dL (7.0 mmol/L) or higher on two separate tests is consistent with a diabetes diagnosis. Always confirm with your healthcare provider — individual context matters.
03
For non-diabetic adults, blood glucose typically peaks about one hour after eating and should return to below 140 mg/dL (7.8 mmol/L) two hours after a meal. Readings of 140–199 mg/dL (7.8–11.0 mmol/L) at the two-hour mark suggest impaired glucose tolerance (prediabetes). At or above 200 mg/dL (11.1 mmol/L) indicates diabetes.
04
Blood glucose below 70 mg/dL (3.9 mmol/L) is classified as hypoglycemia and warrants prompt treatment. Levels below 54 mg/dL (3.0 mmol/L) are considered clinically significant hypoglycemia. Levels below 40 mg/dL (2.2 mmol/L) can cause seizures, loss of consciousness, and are a medical emergency. People taking insulin or certain diabetes medications are at greatest risk.
05
The United States adopted mg/dL as the standard for blood glucose measurement before the mmol/L system became widely promoted internationally. Changing a nation-wide clinical standard is complex — it affects lab equipment, reference ranges, patient education, and decades of published research. Both units are scientifically equivalent; the conversion factor is simply 18.0182.
06
Yes. The conversion uses the exact molecular weight of glucose (180.182 g/mol), giving a factor of 18.0182. This is the same factor used in clinical and laboratory practice worldwide. Rounding may introduce a difference of ±1 mg/dL or ±0.1 mmol/L, which is within normal meter variance. This tool is for educational reference; always use a calibrated glucometer or lab test for medical decisions.