The Blood Sugar Unit Converter translates blood glucose readings between mg/dL (United States, used in clinical reports, glucose meters, and lab work) and mmol/L (United Kingdom, European Union, Australia, Canada — the SI standard). Conversion factor: divide mg/dL by 18.0182 to get mmol/L, or multiply mmol/L by 18.0182 to get mg/dL. The number 18.0182 reflects the molecular weight of glucose (180.16 g/mol) divided by 10.
Clinical ranges are unit-specific. A fasting glucose of 100 mg/dL converts to 5.6 mmol/L — both represent the same biological state (top of normal fasting range, approaching prediabetes at 100+ mg/dL or 5.6+ mmol/L per ADA criteria). Postprandial (after-meal) ranges differ from fasting: normal under 140 mg/dL (7.8 mmol/L) two hours after eating; diabetes diagnosed at sustained 200+ mg/dL (11.1 mmol/L).
The calculator outputs not just the converted number but a clinical category (Hypoglycemia, Normal, Prediabetes, Diabetes) based on whether you specify fasting or postprandial context. Hypoglycemia is defined as below 70 mg/dL (3.9 mmol/L) regardless of timing — a medical emergency requiring immediate sugar intake. These thresholds follow American Diabetes Association (ADA), American Association of Clinical Endocrinologists (AACE), and WHO criteria.
Who needs this converter: International diabetics travelling between regions, patients reviewing lab results from foreign systems, families with multinational members comparing readings, healthcare professionals working across reference standards, researchers reading international literature, and continuous glucose monitor (CGM) users whose devices may default to a non-local unit. Always consult your healthcare provider for treatment decisions — this calculator provides only the mechanical unit conversion plus reference ranges.
PrimeCalcPro provides professional-grade tools trusted by businesses and academics.