Blood Sugar Calculator (Converter)
Use our blood sugar calculator to convert glucose units between mmol/L and mg/dL. Includes the blood sugar conversion formulas, a blood sugar conversion table (chart), and guidance on what blood sugar is considered high (hyperglycemic) and how often to check blood sugar.
Blood Sugar Units: mmol/L vs mg/dL
Blood sugar (blood glucose) readings are commonly reported in mg/dL in the United States and mmol/L in many other countries.
A blood sugar converter helps you switch between these units so you can compare results from different labs, glucose meters, or countries.
This calculator converts glucose only (blood sugar). The conversion factor is specific to glucose.
Blood Sugar Conversion Formula
To convert blood sugar between mmol/L and mg/dL, use the standard glucose conversion factor (18).
For glucose, 1 mmol/L ≈ 18 mg/dL.
Divide by 18 to convert back.
A common conversion you’ll see on blood sugar charts.
Blood Sugar Conversion Chart
Blood sugar conversion table from mmol/L to mg/dL (glucose).
| mmol/L | mg/dL |
|---|---|
| 3.0 | 54 |
| 4.0 | 72 |
| 5.0 | 90 |
| 5.5 | 99 |
| 6.0 | 108 |
| 7.0 | 126 |
| 8.0 | 144 |
| 9.0 | 162 |
| 10.0 | 180 |
| 11.1 | 200 |
| 13.9 | 250 |
| 16.7 | 300 |
To convert mg/dL → mmol/L, divide by 18.
How to Convert Blood Sugar
- 1
Enter your blood glucose value.
- 2
Select the unit you have (mmol/L or mg/dL).
- 3
The calculator converts to the other unit using the formulas above.
- 4
Use the conversion chart for quick common values.
Frequently Asked Questions
Multiply by 18: mg/dL = mmol/L × 18. For example, 6.2 mmol/L × 18 ≈ 112 mg/dL.
Divide by 18: mmol/L = mg/dL ÷ 18. For example, 180 mg/dL ÷ 18 = 10.0 mmol/L.
Definitions and targets vary by individual. Many references describe hyperglycemia in diabetes as commonly above ~180 mg/dL (10 mmol/L) 1–2 hours after eating, and some sources note symptoms often appear around ~180–200 mg/dL (10–11.1 mmol/L). Always follow the targets your clinician gives you.
For many nonpregnant adults with diabetes, the lists common targets such as 80–130 mg/dL before meals and under 180 mg/dL 1–2 hours after starting a meal (individual goals can differ).
Blood sugar can change throughout the day based on meals, activity, stress, illness, and medication. Continuous glucose monitors track glucose frequently (every few minutes), which shows how dynamic glucose can be.
It depends on your treatment plan. The notes people may check up to several times per day as directed by their doctor; frequency varies widely based on medications (like insulin), goals, and symptoms.