🩸Blood Sugar Converter

About this tool

Enter a glucose reading, choose its unit and whether it was taken fasting or two hours after eating. The tool converts it and shows the matching category: low, normal, prediabetes range or diabetes range. A reference table lists the key thresholds in both units. Nothing is stored.

Converting blood glucose units

The US reports blood glucose in milligrams per decilitre (mg/dL). The UK, Europe, Canada, Australia and most other countries use millimoles per litre (mmol/L). Glucose has a molar mass of about 180.16 g/mol, so mmol/L = mg/dL ÷ 18.016 (most people round to 18), and mg/dL = mmol/L × 18. For example, 110 mg/dL is 6.1 mmol/L. Standard diagnostic thresholds from the American Diabetes Association and the WHO are: fasting under 100 mg/dL (5.6 mmol/L) is normal, 100–125 (5.6–6.9) is impaired fasting glucose (prediabetes), and 126 (7.0) or higher on two tests suggests diabetes. Two hours into an oral glucose tolerance test, under 140 (7.8) is normal, 140–199 is impaired glucose tolerance, and 200 (11.1) or more is in the diabetes range. Below 70 mg/dL (3.9 mmol/L) is hypoglycaemia, and below 54 (3.0) is clinically significant. Honest limits: home meters have an accepted error of up to about 15%. Diagnosis needs laboratory tests, and people with diabetes have personal targets agreed with their care team. If you have symptoms of a low or very high reading, act on your care plan or get urgent help. Not medical advice. The A1c calculator converts HbA1c to average glucose, and the net carbs calculator is related.

Frequently asked questions