Blood Glucose Unit Converter
Convert blood glucose between mg/dL (USA) and mmol/L (international) instantly.
Includes fasting, pre-diabetes, and diabetes reference ranges in both units.
Why Two Different Units? The United States, Canada (partially), and a few other countries measure blood glucose in milligrams per deciliter (mg/dL). Most of the world — including the UK, Australia, Europe, and Asia — uses millimoles per liter (mmol/L). If you travel, use a foreign glucometer, or read international research, you will encounter both units.
The Conversion Formula The factor 18.0182 comes from the molecular weight of glucose (C₆H₁₂O₆ = 180.16 g/mol): mmol/L = mg/dL ÷ 18.0182 mg/dL = mmol/L × 18.0182
For a quick mental estimate, dividing by 18 (or multiplying by 18) is accurate enough for most purposes.
Reference Ranges (Fasting Blood Glucose) Normal: 70–100 mg/dL (3.9–5.6 mmol/L) Pre-diabetes: 100–125 mg/dL (5.6–6.9 mmol/L) Diabetes (diagnostic): ≥ 126 mg/dL (≥ 7.0 mmol/L) Hypoglycemia (low): < 70 mg/dL (< 3.9 mmol/L) Severe hypoglycemia: < 54 mg/dL (< 3.0 mmol/L)
Post-Meal (2-Hour Postprandial) Ranges Normal: < 140 mg/dL (< 7.8 mmol/L) Pre-diabetes: 140–199 mg/dL (7.8–11.0 mmol/L) Diabetes: ≥ 200 mg/dL (≥ 11.1 mmol/L)
These are general guidelines. Your doctor may set personalized targets based on your age, medications, and health history.