Blood sugar is reported in mmol/L in most of the world and in mg/dL in the United States and some other countries. Glucose converts with a factor of 18: multiply mmol/L by 18 to get mg/dL, or divide mg/dL by 18 to get mmol/L. The converters below cover every common blood sugar test, plus ketones, which people with diabetes often check alongside glucose.
Converters in This Group
| Test | mmol/L → mg/dL factor | Convert | Reverse |
|---|---|---|---|
| Glucose | × 18 | Glucose mmol/L to mg/dL | Glucose mg/dL to mmol/L |
| Fasting Blood Sugar | × 18 | Fasting Blood Sugar mmol/L to mg/dL | Fasting Blood Sugar mg/dL to mmol/L |
| Random Blood Sugar | × 18 | Random Blood Sugar mmol/L to mg/dL | Random Blood Sugar mg/dL to mmol/L |
| OGTT | × 18 | OGTT mmol/L to mg/dL | OGTT mg/dL to mmol/L |
| Ketones | × 10.41 | Ketones mmol/L to mg/dL | Ketones mg/dL to mmol/L |
To convert mg/dL to mmol/L, divide by the same factor. For ready-made tables, see the mmol/L to mg/dL conversion charts.
About These Tests
Glucose
The main sugar in your blood. A normal fasting level is 3.9–5.5 mmol/L (70–99 mg/dL).
Fasting Blood Sugar
Blood sugar after at least 8 hours without food. 5.6–6.9 mmol/L (100–125 mg/dL) is prediabetes; 7.0 mmol/L (126 mg/dL) or higher on two tests indicates diabetes.
Random Blood Sugar
Blood sugar taken at any time of day. A value of 11.1 mmol/L (200 mg/dL) or higher with symptoms suggests diabetes.
OGTT
Blood sugar 2 hours after a 75 g glucose drink. 7.8–11.0 mmol/L (140–199 mg/dL) is impaired glucose tolerance; 11.1 mmol/L (200 mg/dL) or higher indicates diabetes.
Ketones
Blood β-hydroxybutyrate, measured when sugar is high or during fasting and low-carb diets. Home meters report mmol/L; 3.0 mmol/L or higher with high glucose needs urgent medical attention.
How the Factors Are Calculated
Each factor is the molar mass of the substance (g/mol) divided by 10. Factors were last verified on 24 September 2026. Read more in our editorial policy.
Sources
- American Diabetes Association. Standards of Care in Diabetes — Classification and Diagnosis of Diabetes (updated annually).
- IUPAC Commission on Isotopic Abundances and Atomic Weights. Standard atomic weights (used for all molar masses).
Reference ranges vary between laboratories. Use the range printed on your own report and discuss results with your doctor.